SS 306/A16-3
  Serial 011                                      July 14, 1944
  CONFIDENTIAL
 
 

  From:     The Commanding Officer
  To  :     The Commander in Chief, United States Fleet
  Via :     The Commander Submarine Division 141
            The Commander Submarine Squadron 14
            The Commander Submarine Force Pacific Fleet
            The Commander in Chief U.S. Pacific Fleet

  Subject:  U.S.S. TANG (SS 306), Report of Third War Patrol.

  Enclosure:     (A) Subject Report.
                 (B) Track chart. (ComSubPac only)

       1.  Enclosure (A), covering the third war patrol of this vessel conducted
  in the East China Sea and Yellow Sea, during the period 8 June 1944 to 14 July,
  1944, is forwarded herewith.

                                     R. H. O'KANE
 
 

                                    (A) PROLOGUE

       Returned from second war patrol May fifteenth and completed normal refit on
  the thirtieth.  Conducted post repair trials, training with three days underway,
  loaded and departed June 8.

                                    (B) NARRATIVE

                                      JUNE 8-12

  1330 Underway in company with U.S.S. SEALION for MIDWAY, conducting training
  dives, fire control drills, and testing communications for future coordinated
  patrol.

                                    JUNE 12 (-12)

  0800 Arrived MIDWAY, fueled and located motor ground in a brush pigtail.  Held
  dock trial to insure that trouble had been remedied.
  1600 Departed for EAST CHINA SEA at two engine speed.

                               JUNE 12(-12) - 21 (-9)

       Enroute area, delaying an hour near SOFU GAN to tune SJ radar.  As
       experience in training showed that we could clear seven lookouts and the
       OOD from the bridge without delaying the dive, used this number in the
       daytime and kept the SD secured.  We sighted no planes and none apparently
       sighted us.

                                    JUNE 22 (-9)

  1706 Dived thirty miles from YAKU SHIMA prior to passing through COLNETT STRAIT
       after dark.
  2000 Shortly after surfacing picked up 142 megacycle radar, apparently on YAKU
       SHIMA, with our APR-1 equipment, so gave it a wide berth, using our SJ
       periodically and never within forty-five degrees of the island.  Though
       this is an arbitrary safety angle, and island that has radar will most
       certainly have detectors too, and the least we can expect is re-routed
       shipping.

                                    JUNE 23 (-9)

  0350 Made rendezvous with SEALION south of KUSAKAKI SHIMA, a little late as we
       had delayed to investigate a possible SJ contact.  Patrolled submerged
       southwest of the island during the day, but with periodic high periscope
       searches.
  2000 Proceeded to DANJO GUNTO to meet USS TINOSA.

                                   JUNE 24-25 (-9)

  0115 Made scheduled rendezvous with TINOSA and SEALION fifteen miles south of
       DANJO GUNTO.  Executive officer went aboard TINOSA, delivering infra-red
       signalling apparatus, code for coordinated attacks, and TANG's ideas for
       patrolling this area.  With everything in agreement, proceeded northeast
       for submerged patrol south of FUKAE SHIMA, prior to closing KOSHIKI
       STRAITS.
  0808 Sighted small patrol boat and avoided submerged.
  2145 After dodging numerous lighted sampans along the 100 fathom curve, sighted
       a large convoy on the SJ at 20,000 yards, just having emerged from KOSHIKI
       STRAITS.
  2153 As course and speed were at first ambiguous, sent contact report of
       convoy's position only.  SEALION acknowledged.
  2220 Having tracked convoy on courses between 315 and 270 at speeds from 10 to
       16 knots, answered TINOSA's request for convoy course and speed.
  2227 Sent latest course of 230 and speed 12.

       We were in what at first appeared a fortunate position on the convoy's port
       bow, with a three day old moon about to set, but as numerous bow and
       flanking escorts appeared on the radar screen it became evident that
       undetected penetration from ahead or from the flank would be nearly
       impossible.  The composition of the convoy, which had been confused by
       numerous escorts and side lobes, now was clarified with visual sighting.
       There were at least six large ships, in column sections of two, surrounded
       by two circular screens of at least six escorts each, and as we later
       discovered, each section was further escorted ahead and astern.

                                ATTACKS NO'S 1 AND 2

       As the quarter escorts were well dispersed, elected to approach from the
       stern.  We passed between them without difficulty, diverged to starboard
       and avoided a third patrol, and gained position 2500 yards on the starboard
       beam of the last section.

       The leading ship was a large modern four mast or goalpost freighter with
       high composite superstructure topped by a large short stack, believed to be
       (EU) of the AOBASAN MARU class, page 84, ONI 208-J(rev'd).  The second ship
       was a modern tanker with large short funnel, similar (EU) to the GENYO MARU
       or KYOKUTO MARU, page 277 or 279, ONI 208-J(rev'd).  Both ships were
       heavily loaded, and most probably diesel driven as they did not smoke.

  2349 The convoy, now close to NOMO SAKI, had settled on course north at 10 knots
       when we stopped, turned left for straight shots, and fired three torpedoes
       at the freighter, 120 starboard track, range 2600, spread his length by
       constant TBT bearings, followed immediately by a similar spread at the
       tanker, 100 starboard track, range 2450.  All gyros were between 12 right
       and 2 left.  Observed two beautiful hits in the stern and amidships of the
       freighter, timed as our first and third torpedoes.  The second was observed
       to run erratically to the left.  The explosions appeared to blow the ship's
       sides out, and he commenced sinking rapidly.  On schedule, our fourth and
       fifth torpedoes hit under the stack and just forward of the after
       superstructure of the tanker.  His whole after end blazed up until
       extinguished as he went down by the stern.

  0000 We now evaded the closest escort at 1400 yards apparently unobserved, so
       pulled up seven thousand yards from the convoy and five thousand yards from
       where our targets would have been.  Their pips, separating from the convoy,
       had gradually disappeared from the PPI screen however, and only a low
       hanging cloud of smoke marked the spot where they sank.

  0015 Sent message to other boats that we were trailing and gave convoy's set-up,
       and repeated it twenty minutes later at SEALION's request.

  0020 As the only radar interference indicated that our other boats would not get
       in, especially as the convoy was close to NAGASAKI, whose steel mills
       loomed up like Marin Ship, started in for another attack.  Our approach was
       spurred by an escort who closed to fifteen hundred yards as we passed the
       vicinity of the first attack, but unable to see us in the haze of a slight
       overload, commenced dropping terrific depth charges.  He succeeded in
       calling out the dogs however, and our target, which was first tracked at
       ten knots, showed stopped, then a range rate of better than forty knots
       closing!  We had just time to complete a 90 degree turn when he passed
       sixteen hundred yards astern, a modern looking DE.  He spotted us, closed
       for a minute, but our team of overload experts, watching their
       temperatures, got us rolling at 22 1/2 knots in spite of our unconverted #4
       MBT.  Easing off each time he showed a slight angle, we opened the range to
       3400 yards when he illuminated.  Hoping to take advantage of the experience
       of others, we dived a little faster than a rock, encouraged by a sounding
       taken during the chase.  Though his searchlight illuminated the bridge
       diving alarm for our PCO, he still did not spot us, and passed well clear,
       madly echo ranging.

  0200 Now with time to consider, believed the NAGASAKI area would be very
       unhealthy at dawn two hours hence, so surfaced and rounded the KOSHIKI
       islands where we could guard the southern approaches to the straits.

  0500 Commenced submerged patrol.

  1900 Sighted patrol broad on northerly course; avoided.

                                    JUNE 26 (-9)

                                   ATTACK NUMBER 3

  0424 Shortly after crack of dawn sighted ship on the SJ at 8000 yards which had
       just rounded NOMA SAKI from KOSHIKI straits.  We were already on his beam,
       but fog and rain permitted a full power end-around with only occasional
       glimpses of our enemy.  He was a modern sized, split superstructure, MFM
       freighter, similar (EU) to the LKIMA MARU, page 228, ONI 208-J (rev'd),
       tracked at eight knots on courses hugging the coast.  With the freighter
       obscured by rain, dived a thousand yards off his track, range 7000 yards.
       As we were 3000 yards west of BONO MISAKI; a good firing range was insured.
  0551 Turned right for a stern shot as the freighter came out of the rain and
       fired four MK 18 torpedoes, range 1950, 100 starboard track, gyros near
       180, spread his length by constant bearings.  The torpedoes were set on six
       feet as the sea was calm and the loading of the freighter could not be
       ascertained beforehand.  Though we had a zero angle on the boat, two of the
       torpedoes broached several times and then settled down on surface runs,
       throwing plumes in the air.  Needless to say the freighter avoided the
       spread by turning toward.  All exploders operated as the torpedoes hit the
       beach if that is any consolation.  After some gunfire, the freighter took
       refuge in a cove north of BONO MISAKI, and as we were getting set toward
  0640 the beach, surfaced and made a full power dash to the west, unsighted by
       the late arriving patrol boat.

  0958 Dived when overcast lifted.
  1008 Sighted "Betty" searching.
  1608 Sighted "Betty" searching again.
  1758 Sighted "Dave" searching.
  2000 Proceeded to northwest for coordinated patrol with TINOSA and SEALION of a
       suspected SHIMONOSEKI-SHANGHAI traffic route.  Passed numerous lighted
       sampans.

                                    June 28 (-9)

       Conducted submerged high periscope patrol on direct route between
       SHIMONOSEKI and SHANGHAI.
  1945 Continued to the northwest at one engine speed.
  2000 Detected 150 megacycle radar on either SAISHU TO or MARA TO, so rounded
       them at fifteen miles to avoid possibility of detection and followed our
       usual policy of not training the SJ within 45 degrees of known radar
       installations except for a fast periscope sweep.

                                    JUNE 29 (-8)

  0220 When 40 miles northwest of SAISHU TO, detected weak 95 megacycle radar,
       perhaps from the eastern end of that island, and at the same time commenced
       tracking a radar contact near KAKYO TO at 26000 yards.  This proved to be
       side lobes of the island.  The strength of our 95 megacycle radar did not
       increase as we approached KAKYO TO, so this island is eliminated as a
       possible source.
  0441 Commenced submerged patrol near HEN SHO, half way between KAKYO TO and
       SANTAI TO off the southwest coast of KOREA.  This position was close to the
       suspected route across the YELLOW SEA to the CHINA coast.  Low fast moving
       fog patches and fogging periscopes made searching difficult, so came to
       radar depth periodically.

                               ATTACKS NO'S 4A AND 4B

  1140 Sighted a freighter to the north on a westerly course.  Commenced approach,
       but it soon became apparent that we could not reach an attack position
       submerged.  We therefore opened the range on a diverging course, surfaced,
       and commenced and "end-around" bucking a heavy sea.  Reduced visibility
       permitted passing the ship with only occasional glimpses at 15000 yards.
  1600 Having tracked the enemy on course 255 at 7 knots, dived directly on his
       track for periscope attack.  The freighter came on nicely, identified (EC)
       as TAZAN MARU, page 215, ONI 208-J (rev'd).  His masts had been cut off
       level with the top of his stack, but all other details were as shown.  He
       was lightly loaded, but in view of our experience of the twenty-seventh,
       decided that ten feet was the absolute minimum depth setting for this sea.
       After two "dipsey doodles" to adjust position, and with several echo ranges
  1759 and bearings checking, fired two Mk 14 torpedoes, one at his foremast and
       one at his mainmast, 90 port track, range 1250 yards, speed seven.  Raised
       the periscope again to see the smoke of each torpedo at its point of aim,
       but they apparently passed under.  The enemy turned toward and gave us two
       close depth charges shortly after we had reached two hundred feet, fifty
       feet off the bottom.  Fifteen minutes later, as we were approaching
       periscope depth, a loud crackling noise came over sound followed by a third
       fairly close charge.
  1910 We went back down, but searched and surfaced fifteen minutes later with
       nothing in sight.  This points to the possibility that this last was a
       delayed action depth charge used in this shallow water for the purpose of
       keeping a submarine down while the ship escapes.
  2030 It didn't work in this case however, for we made radar contact in a little
       over an hour and commenced tracking again.  Our enemy had gone to the
       north, was tracked on course 040, then 070 at ten knots, heading for KO TO
       and the ten fathom curve off the KOREAN coast.  We closed sufficiently to
       identify him, and then turned the tracking over to the section on watch
       with the plan to attack after moonset on the lee of DIAKOKSAN GUNTO.

                                    JUNE 30 (-8)

       The freighter was a little out in his navigation, however, his track
       passing about fifteen miles north of the islands.  As firing in the lee was
       now impossible and the sea rougher still, determined to attack from a range
       to insure hits even with broaching torpedoes.
  0040 Commenced approach from his starboard bow directly down wind and sea,
       stopped with range 1500, angle on the bow 40 starboard, killed headway
  0101 as he came on, and fired a Mk 14 "feeler" torpedo set on six feet from
       number five tube, range 750 yards, 92 starboard track 6 degree gyro, enemy
       speed nine knots.  In spite of the heavy seas it ran perfectly, its
       phosphorescent track visible among the white caps right to the freighters
       side.  The explosion amidships, just thirty seconds after firing, was as
       beautiful as it was reassuring.  It broke the freighter's back, his stern
       sinking with a down angle, his forward section with an up, in a cloud of
       fire, smoke, and steam.  His gun crew had guts, however, and got off five
       or six shots in spite of their tilting platform.  When they had ceased
       firing we relieved about twenty lookouts in rapid succession, and today our
       crew is discussing single versus multiple torpedo fire.  (We'll continue,
       however, to fire as many as is considered necessary to sink the enemy.)
       The inability of the enemy to sight us is considered due in part to our
       light grey camouflage, ideal for this area, and the known inefficiency of
       lookouts into wind and sea.

  0130 Proceeded to the west for submerged patrol after daylight.

                                     JULY 1 (-6)

       Commenced submerged patrol one hour after dawn, forty miles west of
  0946 KO TO.  Maneuvered to close a sailing junk, and surfaced to look him over.
       He lowered his sails after four rounds of four inch, but our plans to get
       some information from him became unnecessary when our high lookout sighted
       smoke over the horizon.

                                   ATTACK NUMBER 5

  1015 Commenced tracking smoke which quickly developed into two columns, and then
       the masts of two ships.  One ship was zigging at intervals of from three to
       twelve minutes, while the others movements indicated an escort.  After
       gaining position ahead and tracking these ships on base course 260 at eight
  1322 knots, dived for periscope approach and attack.  As the group came on,
       maneuvered for a Mk 18 stern shot at the escort who was about 1500 yards on
       the freighter's starboard bow.  This placed us directly ahead of the
       freighter and insured a stern shot at him if the escort was not hit.  The
       escort was now identified as a small engine aft freighter with gun forward
       and depth charges aft, probably the 1940 series (EU) of the AMAKASU MARU;
       page 270, ONE 208-J (rev'd), changed in that the bridge structure was aft.
       As TDC bearings were lagging, took several echo ranges and found his speed
  1444 had increased to ten knots.  Now with the set-up checking, fired two Mk 18
       torpedoes, one under his foremast, the other under his stack, 100 port
       track, range 1250, depth setting six feet, then went ahead at standard
       speed to gain position on the freighter.

       As the moments dragged out and time for the torpedoes to hit had apparently
       passed, expressed some quiet oaths about electric torpedoes, only to have
       the words jammed down our throats by a swell explosion.  Slowed and looked
       to see the escort's stern in the air in a cloud of smoke, and the freighter
       turning back.  At least half a dozen persons observed this ship sink, timed
       in two minutes and twenty seconds.

                                   ATTACK NUMBER 6

       We now felt that we had the freighter caught between third base and home,
       for he was nearly one hundred miles from the KOREAN coast and his track led
       through the probable positions of both SEALION and TINOSA.  Sent them the
       contact report on the next hourly schedule and continued trailing submerged
       at five knots.  With smoke still in sight, surfaced at dusk and commenced
  1916 overtaking at full power on three engines, charging with the other and the
       auxiliary.  Again we're thankful for our FAIRBANKS-MORSE, for as it later
       proved, our eighteen and a half knots in this combination was every bit
       necessary.

       After radar contact with the enemy had been gained it became apparent that
       we would have to pass him up moon south of KO TO, but with full power on
       four main engines, we were waiting for him with two minutes to spare as he
       approached the southern tip of the island.

  2224 Dived a mile and a half off the island, 1200 yards north of the track of
       the enemy who was now six thousand yards away.  He slowed from eleven to
       nine knots as he passed the southern tip,  but with three echo ranges and
       periscope bearings, the set-up was checking again as we commenced our turn
       for a straight bow shot.  With range 500, 90 port track, gyros near zero,
       fired
  2247 two Mk 14 torpedoes by constant bearings, the first at the middle of his
       after well deck, the second at the middle of his forward one.  The first
       torpedo hit as aimed in twenty seconds exploding the ship's cargo which
       must have been munitions of some sort.  A short section of the bow was all
       that remained intact of the whole ship, and it sank in twenty seconds.  The
       second torpedo was "robbed".

       This was a medium freighter, identified during and after attack number 5
       and at close range by moonlight prior to firing as similar (EU) to SAMARANG
       MARU, page 130, ONI 208-J (rev'd).

  2251 Surfaced close to debris and proceeded sixty miles to west for our usual
       patrol.

                                     JULY 2 (-8)

       Conducted submerged patrol with high periscope searches.
  1007 Sighted masts of two trawlers.

                                     JULY 3 (-8)

       Patrolled as day before.
  2250 Made scheduled rendezvous with SEALION, and executive officer boarded her
       to exchange information.  She we unable to reach our first convoy, and
       failed to receive our message concerning the freighter, but had sunk an AK
       on the way to this expected traffic route.  It will be interesting to
       compare the reports of SEALION and TINOSA with ours. for the expected route
       runs between their areas as assigned by TINOSA, while ours lies to the
       north.  They have in general patrolled on the surface using their SD and
       have been driven down by planes.  Though this may not be conclusive, it
       appears that they have shunted the traffic by us, for we've been patrolling
       submerged, surfacing for a good look now and then, and keeping SD secured.
       We've seen ships and no planes since after our attack on the 27th.  The
       SEALION had decided to patrol the SHANGHAI area while we proceed north.

                            JULY 4 (-8) (WHAT A FOURTH !)

  0005 Set course for position on the direct route between DAIKOKUSAN GUNTO and
       OSEI TO at three engine speed.  As the sky was overcast at dawn, continued
       on the surface, and shortly sighted heavy masts of a ship to the northeast.

                                   ATTACK NUMBER 7

  0408 Stopped, put him astern, and determined his approximate southerly course,
       and commenced a full power dash to get on his track.  We were a bit
       hampered by fifteen trawlers or fishermen, but with the enemy's bridge and
       stack aft already over the horizon, it was their presence which prevented
       our detection.

  0500 With angle on the bow now 5 starboard, dived and continued approach.  The
       massiveness of the ship as it closed resembled a man-of-war, and twenty
       minutes later a wide zig gave us our first good identification look.  Her
       hull and arrangement were similar (EU) to the KUROSIO MARU, page 272, ONI
       208-J (rev'd), with modifications as shown on accompanying drawing.  During
       the next hour we were abaft his beam as he closed the ten fathom curve,
       zigging leisurely.  On our straight course at full speed we closed the
       range continuously however, and though on most observations with angles on
       the bow up to 150 the situation looked hopeless, he finally reached a nine
       fathom finger west of AMMA TO and came back to a southerly course.  Our
       fathometer, which had been showing four fathoms under our keel, now in
       quick succession showed three, two and then merged with the outgoing signal
  0626 so we backed down and fired three Mk 14 torpedoes at stack, amidships, and
       forward by constant bearings, range 1600, 90 starboard track, speed 8,
       depth setting eight feet.  Turned left with full speed and rudder, and
       heard healthy hits timed as our first and second torpedoes.  We slowed and
       looked to see only the bow, stern, and masts sticking our of the water
       under a huge cloud of smoke.

  0631 Surfaced, surrounded by 34 assorted fishing boats obviously awe-stricken.
       There were about fifty survivors in the water and large life boats, but as
       we could not dive in the eight to nine fathoms if we approached closer,
       headed west at three engine speed.  The stern had sunk before we surfaced,
       and as we cleared the area, observed the protruding bow tip go under in
       bubbling foaming water.

       This ship was observed at moderate ranges from various angles for over an
       hour, and the following features indicate that she was converted for use as
       an (XAV) seaplane tender or aircraft transport:  Her masts and booms were
       approximately twice as heavy as those of a large freighter.  Her bridge
       structure was open aft forming a hangar.  Her stern had been extended by a
       large platform with triangular stern piece and was fitted with kingposts
       and long boom.  An auxiliary radio mast topped her after superstructure,
       fitted with several antennas.  The survivors were far in excess of a normal
       tanker crew.  Except for her black stack and masts, she was war color.
       Comparing this ship with similar conversions in available publications, her
       standard displacement is estimated at sixteen thousand.

  0730 When well clear of any small craft which could report our course, headed
       north and dived an hour and a half later, forty miles from the position of
       our attack.

  1500 Commenced hearing very distant explosions, probably 52 miles distant to be
       exact.

  1840 Having passed OSEI TO, sighted smoke beyond the OIYOKU group of islands,
       tracked on a southerly course.  While figuring where and how we could get
       him under a full moon in more than ten fathoms, our problem was solved by a
       faint wisp of smoke to the west.

                                   ATTACK NUMBER 8

       Switched approach to this and closed at standard speed submerged until
       clear of OSEI TO, then surfaced in
  1953 late twilight, but under a full moon.  Twenty minutes later he was sighted
       on the radar at 18500 yards.  We were in a fortunate position ahead and had
       only to move on to his base course of 110 which led toward OSEI TO and the
       bulge of the ten fathom curve.  His long low silhouette was visible at
       15000 yards, so tracked from that range, determining his moderate zigs of
       20 to 30 degrees at 5 to 10 minute intervals.
  2041 Dived and tracked enemy in by radar to 9000 yards, then commenced moonlight
       periscope attack.  As he came on his silhouette developed into a long
       engines aft ship with raked bow, and with tripod mast and king posts
       forward and aft.  Distinctive also was his mushroom topped bridge
       structure.  After closing a left zig at standard speed,
  2128 checked set up with several echo ranges, and fired last two bow torpedoes,
       one at forward end of after superstructure, the other forward of his
       bridge, range 900 yards, 90 starboard track, gyros near zero, depth setting
       eight feet.  The first torpedo hit just aft of the bridge, breaking the
       ships back.  The tripod foremast could be seen in the smoke and debris
       tilting aft as he sank by the middle.  Let the crew
  2131 hear the breaking up noises by the sound-1MC method, then surfaced to pick
       up a survivor.  It was necessary to snake one of the two large overturned
       lifeboats alongside with grapnels, and threaten with tommy gun bursts to
       convince the one visible survivor to come aboard.  Recovering a life ring
       was much simpler.

       Both the new life boats, life ring, and visual observation of the vessel
       before firing show this to have been a new ship.  She does not appear in
       any identification book.  Our PCO and executive officer both observed this
       ship together with the commanding officer prior to firing, and estimate her
       tonnage to be 10000, the same as the modern tanker her hull was designed
       after.  With some assistance as to detail from the prisoner, the silhouette
       of this ship has been drawn and is submitted.  Of interest is the prisoners
       knowledge of the exact position where they were torpedoed, and apparent
       familiarity with shipping routes.  Not so clear are his figures on tonnage,
       which range from 7000 to 10200, but he finally got across the idea that
       this latter figure was iron ore in her holds.  Phonetically her name was
       AMA-KUKA MARU of the YAMASHITA KISEN KAISHU.

  2328 After commencing another approach on what proved to be a sailing junk,
       headed northwest at three engine speed to round KAKUREPPI ISLAND and
       approach the DAISEI group before dawn.

                                    JULY 5-6 (-8)

  0345 Dived for submerged patrol
  0845 Commenced hearing distant explosions, indicating that the opposition is
       still way behind us.
  0917 Sighted distant smoke drawing to the south close to the KOREAN shore, south
       of the DAISEI ISLANDS.  Although this was inaccessible in six fathoms of
       water, it practically assured an early attack against this coastal traffic
       off CHOSEN KAN.
  1942 Proceeded on the surface to CHOSEN KAN (CHOPPEKI POINT).

                                   ATTACK NUMBER 9

  2257 When 8 miles west of CHOPPEKI POINT, after having tracked one side lobe and
       investigated several second pulse echoes, sighted a ship on the SJ at 29000
       yards.  Stopped and tracked it out to 32000 on a northwesterly course at 9
       knots, then commenced a grueling end around.  Under a full moon on a
       rippleless sea, the ship was visible at 20000 yards, so to insure an
       unalerted enemy for our last two torpedoes, passed
  0227 him outside of 15000.  When 30 miles from GAICKOSAN RETTO (BLONDE GROUP),
       stopped on his track seven miles ahead for a final speed and course check,
       then dived on a parallel course for a submerged attack.  Checked the set-up
       by a radar observation at five thousand yards when the freighter was
       temporarily lost in the surface haze, and immediately experienced
       hopelessly fogging periscope.  The set-up checked perfectly, however,
       showing 500 yards off the track, so returned to 60 feet to wet the scopes.
       He was clear and big on the next observation, at 1100 yards by echo range,
  0320 so turned for the stern shot.  Fired two Mk 18 torpedoes, one at his
       mainmast, one at his foremast, range 900 yards, 90 starboard track, gyros
       near 180, depth setting 6 feet.  Both torpedoes hit exactly as aimed and
       there was only floating wreckage and broken life boats in sight when we
       surfaced two minutes later.  The freighter was medium sized, mast funnel
       mast, composite superstructure, similar (EU) to OSAKA MARU, page 132, ONI
       208-J (rev'd).
  0325 As two pips at 16000 yards were closing, perhaps belated escorts, and the
       sky already pink, commenced full power run to the south toward SHANTUNG
  0600 PROMONTORY.  Dived fifty miles from attack and proceeded south at three
       knots.
  1200 Counter attack, seventy miles distant, commenced.
  1848 Surfaced a half hour before sunset and continued the seven hundred mile run
       out of the area.

                                     JULY 7 (-8)

  0427 Shortly after sunrise dived for a "Betty".
  1230 Continued surface running.
  1914 Shortly after sunset, dived a half hour for a distant plane, believed a
       "Betty".
  2055 Picked up 250 megacycle radar, random, training.
  2155 When between DANJO GUNTO and the southern mine field, sighted five equal
       sized pips on the SJ at 16000 yards on our track ahead.  We were at four
       engine speed, which in part accounts for a range of 12000 yards before we
       got them astern.  The night was lightly overcast with a near full moon
       breaking through, but nothing was sighted on a fairly sharp horizon at this
       range.  As we conducted a reverse end-around to get on their quarter,
       tracked the group on course 310, nearly the reverse of our original course,
       then 340, then 060.  Closed their quarter cautiously until blinker
       signaling was sighted at 13000 yards, but no blurbs against the horizon.
       Five legitimate jap ships would contain at least one smoker and would have
       been visible at a much greater range.  Convinced that this was a "killer
       group", undoubtedly directed by our late plane, gave them a wide berth and
       continued toward area boundary.

                                     JULY 8 (-9)

  0500 Commenced submerged approach of southern islands prior to night passage.
  1600 Proceeded on surface.
  1940 Detected 250 megacycle radar.
  2106 A minute after closing GAJA SHIMA light, observed a searchlight over the
       horizon to the right of the islands, and seventeen minutes later picked up
       153 megacycle radar with random training.
  2145 153 megacycle radar signal steadied at maximum strength, apparently trained
       on us.  As we were already between GAJA SHIMA and TAIRA SHIMA at four
       engine speed, continued through the NAGANO STRAIT into a rising moon.  The
       153 megacycle radar remained steady with maximum signal as we passed
       NAGANONO SHIMA, indicating its location there.  Five small vessels, two of
       them smoking, heading from north and south into the strait, may have been
       patrols.  If so, they were a little late, and no difficulty was experienced
       in keeping their bearings drawing aft with TANG at full power.
  2300 Set course east, but continued at four engine speed during the night.

                                     JULY 9 (-9)

  0839 Dived for half an hour and apparently avoided detection by a distant low
       flying plane.
  1210 Sighted flare, and friendly submarine surfaced about 4000 yards on our
       starboard quarter.  For the benefit of his fire control party, our base
       course was 090, speed 17, following cam #1 of our zig clock, making 15.8
       good along the track.
  2200 Sent message to ComSubPac concerning results, and information concerning
       killer group and departure for other boats.

                                    JULY 10 (-9)

  1030 Dived for fifteen minutes to avoid detection by a transport plane on a
       southerly course.

                                    JULY 14 (+12)

  1200 Arrived Midway.

                                     (C) WEATHER

       Normal for all localities patrolled.

                                (D) TIDAL INFORMATION

       No information not previously reported.

                                (E) NAVIGATIONAL AIDS

  1.   OSEI TO             NORMAL CHARACTERISTICS
  2.   KAKUREFEI PETTO     NORMAL CHARACTERISTICS
  3.   SHUSEI TO           NORMAL CHARACTERISTICS
  4.   DANJO GUNTO         NORMAL CHARACTERISTICS, BUT LIGHTED INTERMITTENTLY
  5.   GAJA SHIMA          NORMAL CHARACTERISTICS
  6.   SHIMO KOSHIKI       NORMAL CHARACTERISTICS
  7.   MATA TO             DIMMED
  8.   KO TO (DAIKOKUZAN GUNTO) NORMAL CHARACTERISTICS

                                  (F) SHIP CONTACTS

       See page 19 A.

                                (G) AIRCRAFT CONTACTS

       See page 20

                                   (H) ATTACK DATA

       See page 21

                                      (I) MINES

       None contacted

                   (J) ANTI SUBMARINE MEASURES AND EVASIVE TACTICS

       Except for the first convoy only one escort was encountered.  The Japs were
       obviously unprepared and several hours late in their searches and
       indiscriminate depth charging and bombing.  Evasion consisted of clearing
       the vicinity of the attack at high speed on the surface.

                            (K) MAJOR DEFECTS AND DAMAGE

       None.

                                      (L) RADIO

       Both reception and transmission were satisfactory.  Tests of the lower
       frequencies assigned to submarines were conducted with the U.S.S. SEALION
       while enroute Midway.  The results were startling in that the lowest two
       frequencies would not carry beyond six thousand yards in daytime and eleven
       thousand yards at night even with maximum power.  It was also found that
       with minimum power the range of 2204 KCS could be reduced to about twenty
       miles.  The data recorded though incomplete will be submitted to the Force
       Communication Officer.  It is felt that further tests should be conducted
       to determine the limiting range of various frequencies for specific power
       settings of the TBL transmitter, as these could be of considerable value in
       coordinated attack group operations.  Further it appears that a frequency
       lying between 450 and 2204 is desirable.  It might even be advantageous if
       this fell in a Japanese broadcast band.

                                      (K) RADAR

       SJ Radar

       The SJ Radar gave comparatively little trouble during this patrol.  This
       may have been due in part to its intermittent use, generally at 10 minute
       intervals.  The part failures are listed below:

       Item Number         Description         Number of      Reason for
                                               failures       failure

            12             Crystal                  1         Bad TR tubes
            130            TR tube                  1         Lost vacuum
            434            R 43                     1         Voltage surge
            444            R 44                     1         Voltage surge
            435            R 46                     1         Voltage surge
            325            R 47                     1         Voltage surge
            159            C 1                      1         Voltage surge

       SD Radar

       The SD radar was not used during this patrol.

                               RADAR DETECTOR CONTACTS
 

   Submarine     Date     Freq.  Rotation               Pulse  Probable
   Position                      Sweep Rate             Rate   Location
   18 mi. S. of  6/22/44  95     Random train           600    Yaku Shima
   Yaku Shima

   25 mi. S. of  6/23/44  118    On 10 sec, off 20 sec  60     USS Sealion
   Danjo Gunto

   25 mi. S. of  6/23/44  95     Random train           900    Danjo Gunto
   Danjo Gunto
   25 mi. S. of  6/23/44  234    Random train           60
   Danjo Gunto

   25 mi. S. of  6/23/44  174    Random train           60
   Danjo Gunto
 

   Submarine     Date     Freq.  Rotation               Pulse  Probable
   Position                      Sweep Rate             Rate   Location
   15 mi. 220d   6/24/44  87     Steady on              900
   Nomo Saki

   31d - 57'N    6/25/44  260    Very weak              7 or
   129d - 31'E                                          800

   20 mi. W. of  6/28/44  150    Continuous             900    Saishu To
   Saishu To
   40 mi. NW of  6/29/44  95     Very Weak              900
   Saishu To

   92 mi. West   7/1/44   249    Fairly strong          900
   of Koto

   60 mi. West   7/2/44   55     Random train           900
   of Koto

   40 mi. West   7/3/44   255    Ransom train           900
   of Koto
   40 mi.        7/5/44   249                           900
   bearing 120d
   from
   Kakureppi
   Retto

   35 mi. S of   7/7/44   250                           900
   Saishu To
 

                                    (S)  DURATION

       Days enroute to Midway   4
       Days from Midway to Area 9
       Days in Area             16
       Days enroute to Midway   7
                                36

       Days submerged           13

                         (T)  FACTORS OF ENDURANCE REMAINING
 

   Torpedoes           Fuel                Provisions          Personnel Factor

   0                   25,000              30 days             Indefinite
 

                                (U)  MK 18 TORPEDOES

       The TANG carried Mk 18-1 torpedoes in the after torpedo room.  We
  experienced no difficulties.  Routine was normal following that appearing in
  other patrol reports.  Exchanging of torpedoes from cradles to tubes was not
  found necessary, however.

                                    SHIP CONTACTS
 

    DATE  TIME  LAT    LONG COURSE SPEED   HOW   RANGE           TYPE
  6/24/44 214032-60N 129-48E  320   10    radar  19000    Convoy 6 ships, 16
                                                                escorts

  6/27/44 042431-16N 130-15N 140-    8    radar   8000         Medium AK
                              110

  6/29/44 114034-37N 124-36E  265    7  periscope 8000         Medium AK
   7/1/44 094634-37N 124-36E  250    9    sight  20000   Medium AK - Escort AK

   7/4/44 04- 35-35N 125-51E 100-    7    sight  20000      AO Probable XAV
          0700                110

   7/4/44 195336-06N 125-52E 100-   9.5   smoke  25000         Ore ship
                              042

   7/5/44 225338-10N 124-15E  317    9     SJ    28450         Medium AK
                             SMALL CRAFT

  6/24/44 080832-04N 128-50E  190       periscope 6000       small fishing

  6/25/44 190031-21N 130-04E  045   10  periscope12000          Patrol

  6/26/44 062031-20N 130-02E  145       periscope12000          Trawler
  6/28/44 025331-52N 127-52E              sight   8000         3 Sampans

   7/1/44 070534-47N 124-13E            periscope 8000