JAPANESE EXPLOSIVE MOTORBOATS II

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JAPANESE EXPLOSIVE MOTORBOATS II


Recruiting in the Homeland

While the first hastily-recruited and partly-trained EMB
units were preparing for action in the Philippines, an official programme of
recruitment and training had begun in Japan. The formation of kamikaze aircraft
units was officially announced on 27 October 1944 and, at the beginning of
November, Captain Tameichi Hara was ordered to find volunteers for suicidal
surface weapons among his 400-strong intake of students at Kawatana Torpedo
School. The order was conveyed by Captain Toshio Miyazaki, who brought with him
three shinyo and a number of frogman suits (the latter to equip the fukuryu,
“crawling dragon”, demolition swimmers).

According to Hara, both he and Miyazaki had serious doubts
about the efficacy, and morality, of suicide weapons, but comforted themselves
with the rationalization that, because of the way in which the war had
developed, the men they were training were doomed to die in any case. Calling
together Hara’s students, they explained the nature of the new weapons and
called for volunteers. Each man was allowed to give his decision secretly to
Hara, who guaranteed that no pressure would be exerted. Of 400 men, 200 elected
to remain in conventional torpedo boat training; 150 volunteered for EMB
duties; and 50 were prepared to become demolition frogmen.

Some historians have suggested that Japanese “special
attack” personnel were not volunteers in the true sense – that they were
brain-washed, indoctrinated with the rhetoric of patriotic self-sacrifice,
whipped up into hysteria by senior officers, and made to feel that they would
be branded as cowards if they did not volunteer. That such men as Captain Hara
(who had made his reputation as one of the IJN’s most successful destroyer
skippers) and the naval airman Saburo Sakai (whose status as an “ace” gave him
a prestige that far outweighed his junior rank) seem to have made little secret
of their opposition to suicide tactics; that 50 per cent of Hara’s students saw
no dishonour in opting for non-suicidal duties; and that their decisions were
unquestioningly accepted: all these facts are strong evidence to the contrary.


Rewards and Promotions

Two former shinyo squadron commanders were asked if any
special privileges were granted to EMB volunteers:

“We did get some extra rations, small luxuries such as sake
and sweetmeats. Regarding pay, there was a regulation providing for higher
allowances for special attack personnel, but these were only paid after a man
had left for the front – where money was of little use to him!”

“There was an extra ration allowance, to keep up the men’s
stamina for hard training for night operations; but there were no special
recreation facilities.”

A popular feature of EMB service, although it can hardly
have influenced men faced with a choice between life and death, was the uniform
worn by pilots. Japanese military uniforms were, to western eyes, functional to
the point of sloppiness. EMB pilots, however, were issued with flying suits
which, according to a veteran, “were very popular because they were both smart
and comfortable, allowing great freedom of movement. In addition, each pilot
was issued with a revolver – and this, too, was very popular”. (Many writers on
military psychology have noted the “status symbol” aspect of the hand gun.)

It is often assumed that all special attack personnel went
into action wearing hachimaki emblazoned with patriotic slogans. The EMB pilots
did not, as a former commander explains:

“I don’t know of any EMB units that wore hachimaki; in my
unit, and those of my friends, we certainly didn’t intend to wear them – mainly
because, in a night attack, for which we were trained, a white head-band isn’t
a good idea!”

Officer-man relationships within special attack units were,
according to veterans, generally more relaxed than in conventional formations:
brutal discipline was out of place in a unit where all were sworn to die
together. It should be noted, however, that all Japanese officers were
officially encouraged to form close personal relationships with their men. An
officer was expected to share his men’s meals, visit their homes, take a close
interest in their families – and even lend them money on occasion. He was also
expected to reward minor acts of merit out of his own pocket: Captain Hara
records that he presented his own watch to an exceptionally efficient seaman.
On the other hand, officers and NCOs, down to senior enlisted men, were allowed
to reinforce discipline with kicks, blows and even severe beatings.

It might be claimed that promotion was a bait for special
attack volunteers; but this was a reward received only after death in action.
In the same way, medals – which were awarded for gallantry, the claims of some
western writers notwithstanding – were usually given posthumously. Men killed
in suicide operations received a posthumous promotion of two ranks, compared to
the one-rank promotion given to all Japanese servicemen killed in battle. (This
was of practical value to their families, who received increased pensions – as
well as greater honour.) Shinto doctrine held that seniority at Yasukuni
Shrine, where those killed in battle were re-united as kami (“demi-gods”),
depended on order of arrival rather than rank at the time of death; thus, it
was a favourite joke among enlisted men that their officers, if not among the
first to fall, would find themselves on fatigue duties in the hereafter. The
most common good-luck wish among Japanese servicemen was “See you at Yasukuni!”


PT-boats versus EMBs

Four days after the maru-ni attack at Lingayen, US PT-boat
squadrons arrived in Luzon waters. With air support, they would henceforth be
the major enemies of the EMBs. With the LCI (“Elsie Item”) gunboats and rocket-
and mortar-armed landing craft, the PT-boats – usually without their torpedoes,
but bristling with as many 40mm, 37mm and 20mm guns, heavy machine guns and
rocket launchers as could be “found” and fitted on improvised mounts –
constituted the “Cactus Navy”, charged with the interdiction of Japanese inter-island
traffic and the destruction of the EMBs in their concealed bases. The US Navy’s
success in seeking out and destroying the suicide craft before they could be
committed to action was facilitated by the breaking of Japanese codes – the
“Ultra”/“Magic” intelligence operation – and also by the capture at Gehh islet,
during the Kwajalein operations of early 1944, of a large number of secret
charts of Japanese-held anchorages throughout the Pacific.

From early 1945 onward, it is difficult to speak with any
certainty of the deployment of individual EMB units. Harried from sea and air,
unit and sub-unit commanders were forced to attack when and where opportunity
decreed and, apart from the two mass attacks described below, were largely
confined to “run-and-hit” sorties by small groups or individual boats. In spite
of their theoretical range, the difficulties of maintenance, the unreliability
of engines and the vulnerability of small boats to weather conditions made it
hard for EMBs to attack enemy vessels other than those close inshore. Their
best hope was to lie hidden near the shore line, on launching dollys that could
be run down rails to the water’s edge, carefully camouflaged, in areas where
Allied landings were expected. If the EMBs had been the “high-speed craft”
envisaged by their originators, they might have been more successful; but most
were considerably slower than the Allied escort warships deployed to counter
their attacks.

In May 1945, the US Navy issued a “Confidential” bulletin
(CinCPac-CinCPOA Bulletin 126-45) on Japanese suicide weapons, giving the
following advice on counter-measures to EMB attacks:

“Small boat attacks can be expected wherever there is
enemy-held territory nearby which can shelter and hide the craft… Many
attacks have occurred at night, especially between the hours of 2400 and 0400.
Experience has demonstrated the wisdom of having visual lookouts, searchlights,
and machine gun batteries fully manned during these hours … Limitations of
train and depression of armament on most vessels have made it necessary to have
patrols equipped with small arms for firing on approaching small craft … In
preparing such defenses, however, it has been necessary to caution personnel
against illuminating and shooting into friendly ships’ boats.

“Battle experience has shown that suicide boats rarely are
detected by radar, as a result of their low freeboard and small size. (And, it
might have been added, because most were constructed of wood.) There have been
instances of a few being picked up by sound gear. The combination of a small
blip on the radar and high speed screws on the sound gear may, together,
foretell the approach of this craft.”

However, the best counter-measure proved to be aggressive
daylight patrolling by PT-boats and aircraft, to destroy the EMBs in their
bases. Typical actions took place near Lingayen on 29–31 January 1945. On 29
January, 10 maru-ni on a beach near San Fernando were destroyed by the gunfire
of PT-523 and PT-524, covered by aircraft of 85th Fighter Command. Farther
south on the same day, a maru-ni base on Batangas Bay, southern Luzon –
reported to US forces by Filipino guerrillas – was raided by four PT-boats from
Caminawit Point, northern Mindoro, where 25 PT-boats were based under the
command of LtCdr N. Burt Davis. Supported by two P-38 Lightning fighters
(“fork-tailed devils” to the Japanese) and two B-25 Mitchell bombers, which
silenced shore batteries, the PT-boats strafed the shore for more than one
hour, destroying several maru-ni.

Next day, LtCdr Davis took two PT-boats, covered by two
aircraft, into Batangas Bay, and led ashore a party to capture an intact EMB,
which they attempted to tow back to Caminawit Point. But Davis’s force, without
air cover on the homeward run, was attacked by trigger-happy US aircraft which
sank the maru-ni. The EMB base at San Fernando was hit again on 31 January,
when two PT-boats supported by P-38 fighter-bombers claimed to have destroyed
five suicide boats and many other small craft.

Date: 31 January – 1 February 1945

Place: Nasugbu, southern Luzon, Philippines

Attack by: Shinyo EMBs, Imperial Japanese Navy

Target: US landing craft and escorts

On 31 January 1945, two regimental combat teams of the US
11th Airborne Division were landed against little opposition at Nasugbu, just
south of Manila Bay. Because of the landing area’s steep gradient, several tank
and infantry landing craft were forced to wait off the beaches until they could
unload on the high tide at 2400. Japanese EMBs were known to be in the area,
and appropriate precautions were taken to guard the transports. Three
destroyers and the amphibious force flagship USS Spencer (Rear-Admiral William
M. Fechteler) were on general patrol. Ranged in a 5-mile (8km) arc around the
beachhead were the DE Richard W. Suesens and the submarine-chaser PC-623 to the
north; the DE Tinsman; and the DE Lough and sub-chaser PC-1129 to the south.
Within this screen, close to the transports, were the destroyers Flusser and
Claxton.

Although the sea was calm, a full moon rising in a cloudless
sky soon after 2100 made EMB operations more hazardous. Nevertheless, a shinyo
squadron that had recently established a base on Balayan Bay, some 25nm (29
miles, 46km) northwest of Nasugbu, was ordered to sortie.

At around 2235, PC-1129 registered the intruders and radioed
a warning of “skunks in the area”. LtCdr Blaney C. Turner of Lough immediately
ordered his crew to general quarters and headed for the action, soon sighting
20 or more boats in line ahead formation. Lough manoeuvred for a position from
which she could enfilade them, but before she could fire the shinyo had
overwhelmed PC-1129, swarming in from all angles as the 280-ton (284 tonne)
escort blazed away with her single 3in (76mm) gun and 40mm AA. Two shinyo were
blown apart, but a third rammed PC-1129 amidships, tearing a 6ft (2m) gash at
the waterline. The subchaser capsized and sank.

Meanwhile, Lough had scattered the remaining shinyo with
enfilading 40mm fire. Abandoning their attempt to reach the transports, the
shinyo broke into small groups and attempted to engage Lough, Tinsman and
Claxton. The latter, illuminating with starshell, found herself the target of a
new menace: a torpedo was fired by a unseen opponent which Lough’s battle
report designated a midget submarine. (It is more likely that one or more of
the Japanese MTBs of Torpedo Boat Squadron 31, based at Manila, had ventured
out to support the shinyo.) But the torpedo was evaded and the shinyo, having
taken heavy losses – Lough alone claimed six destroyed – withdrew. The Japanese
claimed to have sunk or damaged eight ships: in fact, PC-1129 was the only
loss, and all but one of her 80-strong crew survived. Two EMBs, stragglers from
the night attack, were sunk next morning by patrolling aircraft.

Next night, US warships were naturally on full alert at
Nasugbu. Admiral Fechteler had requested support from LtCdr Davis’s
Caminawit-based PT-boats, and Davis had sent PT-77 and PT-79 to patrol off
Talin Point, 6nm (7 miles, 11km) south of Nasugbu. The PT-boats were instructed
not to go north of the Point, into waters where Fechteler’s ships were
patrolling with orders to shoot on sight. Although the PT-boats obeyed, they
were sighted and pursued by Lough and the destroyer Conyngham and, apparently
failing to make speedy and adequate recognition signals, were taken under 5in
(127mm) and 40mm fire at c.1,200yds (1100m) range. Knowing the attackers were
US ships, Lt John H. Stillman headed PT-77 towards the destroyers, making the
light signal “PT … PT … PT …”. This only convinced the destroyer skippers
that the small craft were Japanese: for to advance under fire while making
improvised “friendly” signals seemed an obvious ruse for a suicide attacker.
Both PT-boats were sunk by the destroyers’ gunfire – the last PT-boats lost in
action in the Pacific. It was, says the US Navy’s historian, a victory for the
suicide boats, which had so unsettled the US seamen.

The US Navy was able to declare the Lingayen area “clear” by
11 February, by which time the strength of the EMB units had been seriously
depleted both by losses and by the re-deployment of many support personnel as
infantry. From late January onward, the EMBs had suffered considerably at the
hands of Luzon-based Douglas SBD Dauntless dive-bombers of the US Marine Corps
(the “Diving Devil-dogs”). Especially heavy losses were sustained during the
massive naval bombardment of Corregidor begun on 10 February: a few shinyo made
a desperate sortie against the bombardment force on the night of 10–1 February,
but with no result other than the loss of more boats. By mid-February, fewer
than 60 of the Corregidor-based shinyo commanded by LtCdr Oyamada remained
operational. However, in seeking the capture of the island fortress, the US
invaders gave the EMBs the chance to make their last mass attack.

Date: 15–16 February 1945

Place: Mariveles, Corregidor Channel, Luzon

Attack by: Shinyo EMBs, Imperial Japanese Navy

Target: US landing ships

On 15 February, Rear-Admiral A. W. Struble’s Amphibious
Group 9 put ashore some 4,300 US troops at Mariveles on the north shore of the
Corregidor Channel. As at Nasugbu, a steeply-sloping beach and heavy surf
delayed the operation, and at nightfall five LSTs were still waiting to unload
on the next high tide. Rear-Admiral R. S. (“Count”) Berkey was understandably
unwilling to hazard his cruisers and destroyers in the restricted waters of
Mariveles harbour in darkness. The warships withdrew, leaving five LCS(L)s –
246-ton (250 tonne) converted landing craft, each mounting at least six 40mm
guns, 10 rocket launchers and many smaller automatic weapons – to guard the
tank landing ships.

Oyamada ordered that all shinyo still operational at
Corregidor should be committed to an attack on these tempting targets little
more than 5nm (5.75 miles, 9km) away. After nightfall, about 50 shinyo were
wheeled from their revetments on dollys to the water’s edge. The five LCS(L)s,
ranged across the mouth of Mariveles anchorage, made radar and visual contact
with the attackers at around 0315; by that time, the shinyo were so close that,
although they failed to pierce the defensive screen, they were able to swamp
the armoured support craft with mass attacks. LCS(L)-27 was the first US ship
to open fire; her gunners claimed to have blown apart five shinyo before a
sixth detonated so close aboard that she was severely damaged and was run
ashore by her skipper. LCS(L)-7, LCS(L)-26 and LCS(L)-49 were all sunk by
massive explosions – but so many shinyo were lost in the fierce melee that they
could not press home their attack to the transports.

Japanese artillery observers at Mariveles signalled to
Corregidor: “Shinyo have sunk one cruiser, one destroyer and two transports”.
There were no Japanese survivors to set the record straight, for not one shinyo
returned from the sortie. The destroyers Conyngham, Nicholas and Young
accounted for several stragglers in the light of morning. The surviving
personnel of the Corregidor EMB squadrons fought to the death as ground troops
following the US airborne and amphibious invasion of 16 February 1945.

■ EMBs
at Iwo Jima and Okinawa

Neither shinyo nor maru-ni played a significant part in the
defence of Iwo Jima. Shinyo Squadrons 3 and 4 were transported from Hahajima to
Iwo Jima – some 175nm (200 miles, 325km) to the south – shortly before the US
landings. On 16–9 February, however, the big guns of Rear-Admiral Bertram S.
Rodgers’s Task Force 54, with air cover from the 10 escort carriers of
Rear-Admiral C. T. Durgin’s Task Group 52.2 and support from USAAF bombers,
subjected Iwo Jima to a massive pre-invasion bombardment. LtGen Tadamichi
Kuribayashi’s 23,000-strong garrison was able to weather the storm without
great loss, in a labyrinth of caves and bunkers, but there were few suitable
beach areas on the small, volcanic island for the concealment or protection of
EMBs, and most were destroyed

At the end of March 1945, LtGen Mitsuri Ushijima’s 32nd Army
stood ready to fight to the death in the central Ryukyus – on Okinawa and its
offshore islands. Of Ushijima’s garrison of some 100,000 men, about 9,000 were
naval personnel under Rear-Admiral Minoru Ota. The naval special attack forces
comprised a midget submarine unit, Dragon Squadron No 2, with seven boats,
based on Unten on the east side of the Motobu Peninsula, northwest Okinawa; and
Shinyo Squadrons Nos 22 and 42.

Both EMB squadrons suffered considerable pre-invasion
losses. SS 22, formed late in December 1944, reached Okinawa on 15 January, and
thus had time to prepare a satisfactory base for its 45 boats near Chinen,
southeast Okinawa. But on 14 March, while the squadron was engaged in
early-morning training offshore, a surprise raid by B-24 bombers killed 15
pilots and sank several boats. SS 42 left Japan much later and the squadron’s
transports sustained heavy air attacks; by the time SS 42 reached its base at
Yonabaru, in the south of Nakagusuku Wan (Bucker Bay), southeast Okinawa, on 1
March, it had only 17 operational boats remaining.

The Imperial Army’s maru-ni were much stronger, with eight
units – Advanced Combat Units Nos 1, 2, 3, 4, 26, 27, 28 and 29; with a total
establishment of 720 boats – deployed in the Okinawa area. Some 300 of these
boats were based on the Kerama Retto, the chain of small islands about 15 miles
(24km) west of Okinawa. Of the remainder, most were based on the Motobu
Peninsula or in and around the estuary of the Bisha Gawa at Hagushi,
west-central Okinawa, which was thought, rightly, to be a likely area for
landings.


Clearing the Kerama Retto

Vice-Admiral Richmond K. Turner, commanding the Joint
Expeditionary Force in “Operation Iceberg”, was well aware of the importance of
the Kerama Retto to the Okinawan operations and was determined to secure them
in advance of D-Day (1 April) as a supply and repair base. The Japanese
garrison was weak – no more than 1,000 men – and, by unhappy chance, the US
77th Infantry Division’s landing on 26 March came at a time when the overall
maru-ni commander, Captain Omachi, and many of his pilots were away on a training
exercise in Okinawa itself. Thus, no general order was given for maru-ni to
strike at the invasion force off Kerama Retto: about 10 boats are believed to
have sortied, but without result.

At a cost of only 31 dead and 81 wounded, US forces had by 31
March secured a vital base and, an important contribution to the safety of the
Allied invasion fleet, had destroyed or captured most of the Kerama Retto-based
maru-ni. Some 250 EMBs were found in concealed anchorages or improvised
shelters, many on launching dollys. Some had been carefully booby-trapped;
others had been wrecked by their crews. A US Army report stated that the boats
were powered by “6-cylinder Chevrolet automobile engines” and that each carried
two 264lb (120kg) depthcharges on a stern rack – “the fragility of the boats
made survival highly unlikely”. A later US Navy report stated that the boats
captured in the Keramo Retto were one-man craft, some capable of no more than
6.5kt (7.5mph, 12kmh), carrying either time-fuzed or impact-fuzed charges.
Charts and operational instructions captured with the boats not only gave
detailed information on the deployment of EMBs at Okinawa but also enabled the
US Navy to draw up a manual of suicide boat tactics, based on captured Imperial
Japanese Army instructions.

A few maru-ni survived in the Kerama Retto to strike back.
On the night of 28 March, one of a group of boats hidden on Hokaji Shima made a
well-judged attack on the net-layer USS Terebinth as she lay at anchor. The
maru-ni made its approach from dead ahead, so that the “horns” of the netlaying
gear on the US vessel’s bows prevented her guns from being brought to bear, and
itself opened fire with a light machine gun as it rushed in. Then, with every
prospect of success, the maru-ni turned sharply to starboard, dropped a single
depthcharge some 50ft (15m) from Terebinth, doing no damage, and raced away
into the darkness. The pilot may have lost his nerve; or he may have been
over-cautious in the hope of preserving his boat to make further attacks. On
the same night, three maru-ni attempting to make the passage between Tokashiki
Shima and Okinawa were intercepted and sunk by LCI gunboats; and three more
which attempted a dawn attack on LSM(R)-89 were destroyed by the
rocket-gunboat’s fire.

The last attacks by Kerama Retto-based EMBs appear to have
been made on 29 March, in daylight, when the destroyer-transport USS Bunch,
with escorting destroyers, took Underwater Demolition Teams into the Bisha Gawa
estuary to destroy the maze of landing obstacles the Japanese had erected
there. Two maru-ni racing in from seaward, probably from Keise Retto were
destroyed by gunfire; so was a third which emerged at high speed from the
estuary itself.


Attacks by Okinawa-based EMBs

The part played by Japanese EMBs in the long and bitter
struggle for Okinawa was a minor one. Nevertheless, the suicidal surface craft
scored some successes, and most certainly contributed to the adverse effect on
Allied morale exerted by the long-sustained and suicidal resistance of
Okinawa’s defenders from 1 April 1945 onward.

During the immediate pre-invasion air bombardment of Okinawa
on 25–31 March, EMB bases had a target priority second only to airfields. The
Bisha Gawa area, where many EMBs were based, was subjected to heavy napalm
strikes on 28 March; the midget submarines and shinyo at Unten received special
attention on 29 March. On the latter day, SS 42 suffered heavily: 15 boats
sortied after dark, found no targets and, returning to base after dawn, were
caught by US aircraft and sunk. A group of boats from SS 22 was also sighted by
aircraft and tracked back to its base at Chinen, which was thereafter subjected
to heavy bombing. By 31 March, the two squadrons had fewer than 20 operational
boats between them.

The maru-ni at Bisha Gawa also took severe losses from air
attack. Enough survived, however, to make a mass attack on the night of 31
March, as the Allied invasion armada moved towards the Hagushi beaches. Some 50
maru-ni sortied, but, betrayed by the roar of their engines and by the
phosphorescence of their wakes on the moonlit water, they came under fire while
still far from the soft-skinned transports. But at least one maru-ni penetrated
the wall of fire to ram the 520-ton (528 tonne) LSM-12. Temporarily kept afloat
despite a gaping hole amidships, the landing ship at last foundered on 4 April.

As US troops poured ashore on the western beaches on 1
April, the shinyo squadrons on the east coast launched their lust attacks. Lt
Imoto, commander of SS 42, played his shakuhachi (a bamboo flute) as he led out
his two remaining boats. Neither boat was seen again, although a Japanese
observation post ashore reported “a pillar of fire in Nakagusuku Wan”.

The end of SS 22 was not long delayed. By 3 April, the US
ground advance threatened the Chinen base from landward and Admiral Ota’s HQ
ordered all remaining shinyo to sortie. SS 22 had 14 boats left; but because so
many launching dollys had been destroyed in air raids, only four could be got
into the water, on the night of 3–4 April. Each manned by two men (for
supernumary pilots had insisted on the honour of taking part), the four shinyo,
led by Lt Toyohiro, headed south. Not far from Chinen they sighted two LCI
gunboats, and split into two pairs, one to each enemy vessel. Although the
LCI(G)s were capable of only about 14kt (16mph, 26kmh), the poorly-engined
shinyo were probably even slower, especially with double crews; and one pair of
EMBs missed their target, passing astern. But the boat crewed by POs Ichikawa
and Suzuki was successful: their shinyo rammed and sank LCI(G)-82, killing 8
and wounding 11 of her crew of 65.


Successful Strikes by Maru-ni

Although LCI gunboats claimed to have destroyed 71 suicide
boats during the first week of April, and although US ground forces were
over-running their bases, the Imperial Army’s maru-ni still retained some
offensive capability. ACU 26 had established a well-concealed base at Naha on
the southeast coast, just north of the Oroku Peninsula and only some 10nm (11.5
miles, 18.5km) south of the Hagushi beaches. From this base, a group of maru-ni
launched an attack on US transports and escort off the “Brown” landing beaches
at c.0300 on 9 April. Approaching in darkness, the maru-ni split into two
groups to assault transports and escorts simultaneously.

At 0400, as the 2,050-ton (2083 tonne) destroyer USS Charles
J. Badger (Cdr J. H. Cotten) was lying to after completing a shore bombardment
task, she was the victim of a “text-book” attack by a maru-ni. Charging out of
the darkness, the EMB unloaded a single time-fuzed depth charge and wheeled
away before Badger could open fire. The explosion tore a gash in the
destroyer’s starboard side and sent sea water pouring into the after
engine-room. Although there were no casualties, the destroyer was only with
difficulty kept afloat. Towed to Kerama Retto, she took no further part in the
war.

Concentrated fire from the destroyer USS Purdy deterred
another maru-ni, which dropped a depth charge too far away to do any damage.
The 6,318-ton (6419 tonne) attack cargo ship USS Starr had a closer escape: a
maru-ni on a collision course struck a medium landing ship, LSM-89 moored
alongside, inflicting only superficial damage. The destroyer USS Porterfield
was also damaged – by gunfire from other US ships as they lashed at the
diminutive attackers. Even after the maru-ni had all been sunk or driven off,
further fire was necessary to dispose of swimming survivors armed with hand
grenades.

For the rest of April, maru-ni activity was limited to lone
sorties. An EMB damaged the motor minesweeper YMS-331 on 15 April; and a
greater blow was struck by a single maru-ni in Nakagusuku Wan on 27 April, when
the 2,050-ton (2083 tonne) destroyer USS Hutchins was “lifted several feet” by
the impact of a suicide boat. With 18 men wounded and her port engine and
propeller shaft wrecked, Hutchins remained out of commission until the war’s
end. Two days later, the rocket-gunboat LCS(L)-37 was rammed; only four of her
70-strong crew were wounded, but the fire support craft was a write-off.

The last significant operation by suicide boats at Okinawa
took place on 3–4 May, when almost all the remaining EMBs were deployed in the
amphibious phase of a Japanese counter-offensive. Some served as communication
boats and transports; others made suicidal attacks timed to coincide with
kamikaze air strikes and banzai attacks by ground troops. (Naval shinyo
squadrons ordered to Okinawa from Formosa, Ishigaki-shima and Amami-O-shima to
support these attacks failed to arrive because their transports were bombed en
route.) Some 15 maru-ni were expended in attacks that resulted in serious
damage to the 4,380-ton (4450 tonne) cargo ship USS Carina.


Admiral Ota’s Suicide

By mid-May, the EMBs at Okinawa had spent their strength.
The surviving members of the EMB units fought on as infantry, holding out on
the Oroku Peninsula, around Naha, until mid-June, and putting up a savage
resistance to the advancing US 6th Marine Division.

On 6 June, Rear-Admiral Ota sent a signal to Tokyo praising
the gallantry of the naval troops and expressing “deepest apologies to the
Emperor for my failure to defend the Empire more efficiently”. His last message
to General Ushijima, on 10 June, announced that “the Naval Base Force is now
dying with glory”. When US Marines entered Ota’s HQ on 15 June, they found the
Admiral and five of his staff, their bodies reverently composed, lying with
their throats cut. Some 200 more naval personnel had committed ritual suicide
elsewhere in the Admiral’s headquarters.

Thereafter, the EMBs would be deployed for the final defence
of Japan.

By MSW
Forschungsmitarbeiter Mitch Williamson is a technical writer with an interest in military and naval affairs. He has published articles in Cross & Cockade International and Wartime magazines. He was research associate for the Bio-history Cross in the Sky, a book about Charles ‘Moth’ Eaton’s career, in collaboration with the flier’s son, Dr Charles S. Eaton. He also assisted in picture research for John Burton’s Fortnight of Infamy. Mitch is now publishing on the WWW various specialist websites combined with custom website design work. He enjoys working and supporting his local C3 Church. “Curate and Compile“
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