Army Sea Raiding Battalions

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john whitman
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Army Sea Raiding Battalions

#1

Post by john whitman » 25 May 2010, 10:49

To all:

There is a nice web site at //www.asahi-net.or.jp/~un3k-mn/sinyo-his.htm that lists Navy Shinyo Squadrons.

Is there a web site that lists the Army Sea Raiding Battalions...Marine Advance Combat Units...maru-ni boats?

Thanks for the help.

John

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Re: Army Sea Raiding Battalions

#2

Post by wibble » 02 Jan 2015, 11:53

Fantastic source, thanks. But I think these units are Navy not Army since only the Navy used Shinyo?

The Army used the Maru-ni which was similar but intended to drop depth charges.

HOWEVER.... all the pictures I can find on the net seem to be of Shinyo not Maru-ni (possibly because I do not know the kanji for Maru-ni so cannot search in Japanese... and "Maru-ni" may be "Maru-2").

Does anybody know of any solid info n the Maru-ni, particularly photos of it?


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Re: Army Sea Raiding Battalions

#3

Post by fontessa » 03 Jan 2015, 01:03

Hello wibble,
wibble wrote: Does anybody know of any solid info n the Maru-ni, particularly photos of it?
http://www.asahi-net.or.jp/~un3k-mn/riku-rehis.htm

Maru-ni [Secret name was 連絡艇 Maru-re (liaison boat).]
Length: 5.6 m
Width: 1.8 m
Draft: 0.26 m
Displacement: 1.5 tons
Max Speed: 23 ~ 25 knots
Endurance: 3.5 hours
Crew: 1
Power plant: Automobile engine (60 hp)
Armament: 250kg depth charge x 1 or 120kg depth charge x 2
Maru-ni.jpg
Maru-ni.jpg (56.8 KiB) Viewed 1409 times
海上挺進戦隊(Sea Raiding Squadron) used Maru-nis.
The organization of it was the below.
- HQ
- 3 companies
---- HQ and 3 groups for each
Total 104 men and 100 Maru-nis

50 Squadrons were formed.
- 1st Sea Raiding Squadron: formed at Iwao Island*, on 2 September 1944 (Shipping HQ)
- 2nd Sea Raiding Squadron: formed at Ujina on 1 September 1944 (Shipping HQ)
- 3rd Sea Raiding Squadron: formed at Hiroshima on 1 September 1944 (Shipping HQ)
- 4th Sea Raiding Squadron: formed at Iwao Island on 13 September 1944 (Shipping HQ)
- 5th Sea Raiding Squadron: formed at Hiroshima on 15 September 1944 (10th Area Army)
- 6th Sea Raiding Squadron: formed at Ujina on 16 September 1944 (41st Army)
- 7th Sea Raiding Squadron: formed at Ujina on 16 September 1944 (41st Army)
- 8th Sea Raiding Squadron: formed at Ujina on 18 September 1944 (10th area Army)
- 9th Sea Raiding Squadron: formed at Ujina on 18 September 1944 (41st Army)
- 10th Sea Raiding Squadron: formed at Ujina on 10 July 1944 (41st Army)
- 11th Sea Raiding Squadron: formed at Ujina on 5 October 1944 (41st Army)
- 12th Sea Raiding Squadron: formed at Etajima on 1 October 1944 (14th Area Army)
- 13th Sea Raiding Squadron: formed at Ujina on 5 October 1944 (41st Army)
- 14th Sea Raiding Squadron: formed at Ujina on 5 October 1944 (41st Army)
- 15th Sea Raiding Squadron: formed at Ujina on 5 October 1944 (41st Army)
- 16th Sea Raiding Squadron: formed at Ujina on 5 October 1944 (41st Army)
- 17th Sea Raiding Squadron: formed at Ujina on 15 October 1944 (41st Army)
- 18th Sea Raiding Squadron: formed at Ujina on 15 October 1944 (41st Army)
- 19th Sea Raiding Squadron: formed at Ujina on 15 October 1944 (41st Army)
- 20th Sea Raiding Squadron: formed at Ujina on 15 October 1944 (10th Area Army)
- 21st Sea Raiding Squadron: formed at Ujina on 15 October 1944 (10th Area Army)
- 22nd Sea Raiding Squadron: formed at Ujina on 25 October 1944 (10th Area Army)
- 23rd Sea Raiding Squadron: formed at Ujina on 25 October 1944 (10th Area Army)
- 24th Sea Raiding Squadron: formed at Ujina on 25 October 1944 (10th Area Army)
- 25th Sea Raiding Squadron: formed at Ujina on 25 October 1944 (10th Area Army)
- 26th Sea Raiding Squadron: formed at Etajima on 25 October 1944 (32nd Army)
- 27th Sea Raiding Squadron: formed at Etajima on 25 October 1944 (32nd Army)
- 28rh Sea Raiding Squadron: formed at Ujina on 28 October 1944 (32nd Army)
- 29th Sea Raiding Squadron: formed at Ujina on 28 October 1944 (32nd Army)
- 30th Sea Raiding Squadron: formed at Ujina on 28 October 1944 (32nd Army)
- 31st ~ 38th Sea Raiding Squadrons: Ordered the formation on 23 May 1945 (16th Area Army)
- 39th and 40th Sea Raiding Squadrons: Ordered the formation on 23 May 1945 (15th Area Army)
- 41st~50th Sea Raiding Squadrons: Ordered the formation on 23 May 1945 (Shipping HQ)
* Hiroshima Prefecture

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Re: Army Sea Raiding Battalions

#4

Post by wibble » 03 Jan 2015, 14:59

Great, many thanks. Outwardly it looks so much like the Shinyo that I simply haven't noticed it!

More images of Maru-ni now that i know what I'm looking for. Distinguishing features are angular engine intake and lack of semicircular hatch in bow for mine. Obviously depth charge is obvious when carried.
Image
Image
Image
Image

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Re: Army Sea Raiding Battalions

#5

Post by Akira Takizawa » 03 Jan 2015, 15:34


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Re: Army Sea Raiding Battalions

#6

Post by flakbait » 03 Jan 2015, 21:28

Considering these mass produced cheap fast craft were to be deployed in large numbers against the Allied invasion of Japan it is just as well that the existing units were never seriously allotted the gasoline supplies to train with that their aerial counterparts the Kamikazes barely were. Even just used against the landing waves they had the capability to potentially inflict very serious losses to the initial assault waves that were already reasonably expected to suffer grieviously before they managed to put foot ashore upon Japanese soil. While some Allied planning officers practically laughed off the suicide boats as ineffective `last grasp" desperation weapons even assuming proper fuel supplies would be available, others saw them for the very potent and real threat that they were depending upon the availability of the all critical fuel supplies...and once they were inside the Allied landing waves even shooting at them would obviously as dangerous to fellow Allied forces as to the Maru-ni crewmen; possibly more so. Even assuming few actually were successful, just the disruption a dozen or so such craft would likely cause to a precisely timed and organized landing attempt could be significant. Add in shelling by the defenders and a visit by the "Divine Wind" as well as the odd Kaiten mini sub launching torpedoes against the larger LSTs or LSMs and things don`t bode well for those 1st few waves...

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Re: Army Sea Raiding Battalions

#7

Post by Wellgunde » 04 Jan 2015, 23:02

Are the commanding officers of any of the sea raiding squadrons known?
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fontessa
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Re: Army Sea Raiding Battalions

#8

Post by fontessa » 05 Jan 2015, 13:09

Hello Wellgunde,

According to Unit Brief Histories and Army Transfer and Promotion List No.148 dated 1 July 1945, the commanders of sea raiding squadrons were as follows.
(JACAR C12122417700, C12122417800, C12122417900 and C12120946900)

1st Sea Raiding Squadron: Major Umezawa Yutaka
2nd Sea Raiding Squadron: Major Noda Yoshihiko
3rd Sea Raiding Squadron: Major Akamatsu Yoshiji
4th Sea Raiding Squadron: Major Kaneko Masanori
5th Sea Raiding Squadron: Captain Kondo Mitsuo
6th Sea Raiding Squadron: Major Hibino Saburo
7th Sea Raiding Squadron: Captain Uchida 旭一 Kyokuichi(?)
8th Sea Raiding Squadron: Captain Akiyama Gunji
9th Sea Raiding Squadron: Major Joho Masao
10th Sea Raiding Squadron: Major Sugawara Kyuichi
11th Sea Raiding Squadron: Major Tada Seiji
12th Sea Raiding Squadron: Captain Takahashi Isao
13th Sea Raiding Squadron: Captain Baba Keizo
14th Sea Raiding Squadron: Captain Ejima Motonori
15th Sea Raiding Squadron: Major Ogushi Osamu
16th Sea Raiding Squadron: Captain Tsukii Teikichi
17th Sea Raiding Squadron: Major Tomita Hiroshi
18th Sea Raiding Squadron: Captain Wakabayashi Hajime
19th Sea Raiding Squadron: Captain Ioki Sadashi
20th Sea Raiding Squadron: Captain Sumida Takashi
21st Sea Raiding Squadron: Captain Hayashi Hitoshi
22nd Sea Raiding Squadron: Captain Yoshizawa Makio
23rd Sea Raiding Squadron: Captain Mikuriya Zenzaburo
24th Sea Raiding Squadron: Captain Inada 満偲 Mitsushi(?)
25th Sea Raiding Squadron: Major Tatara Takeo
26th Sea Raiding Squadron: Captain Adachi Mutsuo
27th Sea Raiding Squadron: Major Abe Shigeki
28th Sea Raiding Squadron: Major Homma Toshio
29th Sea Raiding Squadron: Captain Yamamoto Hisanori
30th Sea Raiding Squadron: Major Yamamoto Hisanori
31st Sea Raiding Squadron: Major Tanaka Sotozaburo
32nd Sea Raiding Squadron: Major Hayami Koichi
33rd Sea Raiding Squadron: Captain Sakaguchi Akimi
34th Sea Raiding Squadron: Captain Nishiyama Sadamu
35th Sea Raiding Squadron: Captain Tamura Hajime
36th Sea Raiding Squadron: Captain Ito Shigenobu
37th Sea Raiding Squadron: Captain Umeda Tsuneo
38th Sea Raiding Squadron: Yamashita Sakuo
39th Sea Raiding Squadron: 1st Lieutenant Nakajima Yukio
40th Sea Raiding Squadron: Captain Yamamoto Shoji

Because the 31st ~ 40th Sea Raiding Squadrons were scheduled to be organized in the middle of July 1945, their commanders were appointed on 1 July. On the other hand, the scheduled organization tine of the 41st ~ 50th squadrons was the beginning of September. So their commanders were not be appointed until the end of the war.

fontessa

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Re: Army Sea Raiding Battalions

#9

Post by Mil-tech Bard » 05 Jan 2015, 15:36

Flakbait,

Although it did not make it to the draft Olympic Plans published after the war, the US Navy was in the process of incorporating 200 PT-boats into the Olympic invasion force to deal with the Japanese small suicide boat threat.

The mini-sub threat was going to be partially met extensive day time aerial anti-sub patrols, with a nightly retirement of the invasion shipping for the first weeks of the invasion, plus there would have been extensive anti-sub netting laid around Olympic anchorages in Kyushu, along with early sonar buoys and sea mines.

In addition, before small airstrips were established ashore, US Army L-5 artillery spotter planes-- some of them broadcast TV camera equipped (!) -- would be flying from Brodie device equipped LST's for each US Army beach head. Their high priority targets would be hidden coastal suicide boat and Kaiten launching sites.

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Re: Army Sea Raiding Battalions

#10

Post by flakbait » 05 Jan 2015, 16:56

The fact that the threat from these craft was by then seriously considered as potentially as great as the Kamikaze was recognized to be by the higher Allied commanders says volumes. And the addition of the US Navy PTs particularly could have been effective depending on their tactics; would assume this would be 'pro-active' and would include destroying them in their base camps before the individual craft could sortie...calling in NGF missions and air strikes on these hide outs would also probably be generously and very liberally applied.

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Re: Army Sea Raiding Battalions

#11

Post by Mil-tech Bard » 05 Jan 2015, 21:20

Flakbait,

What it says was that Admiral Turner got end-run to Nimitz by staff officers in the 7th Fleet using ComMTBRonsPac as their agent.

Turner's Olympic plan (Commander, Amphibious Forces, U.S. Pacific Fleet, Operation Plan No. A11-45 (Advance Draft), CAF/A16-3(1), 10 August 1945) only included 36 PT-boats around X+45 days. That is, 45 days after the main troop landings on 1 Nov 1945.

Somebody on either Adm. Thomas C. Kinkaid's or Adm. Daniel Barbey's staff -- having learned the game of long distance invasion plan politics in "General MacArthur's Court" -- went around Turner and got Nimitz to include the majority of available PT-Boats in the Olympic screen plan.

Turrner's staff was slow rolling the transfer of "Philippines Sea Frontier" PT-tender and PT-base logistics to the Kyushu invasion as the war closed.

The following is from the MTB Administrative history on the Fold3 service --
Page 237 (256 of the PDF file)

Some higher echelons had considered introducing
MTB's into the Okinawa area during the heavy fighting, but
ComPhibsPac opposed this action because of difficulties in
recognition. ComTHIRD Fleet, who at first had believed they
could be useful there, later changed his mind, fearing that the
boats could all be destroyed if a typhoon struck the area. ••


Regarding future operations, ComMTBRonsPac had
prepared an estimate of MTB's potentialities around Kyushu
for CinCPac in early June, and shortly thereafter he directed
ComMTBRons7thFlt to evaluate the materiel and personnel of
the SEVENTH Fleet squadrons with an eye to their use in
OPERATION OLYMPIC. CinCPac was then considering decommis -
sioning the older SEVENTH Fleet squadrons; Com7thFlt recom-
mended against this until all need for them was clearly over.

No MTB's had been included in the first disseminated
plans However, in early August,•••


• MBT's did not generally carry a complete BK-BN unit.

•• This later proved to be an unwarranted concern. The
three squadrons at Okinawa weathered a typhoon in September
with little material damage.

••• Conferences between ComPhibaPac and his subordinate
commanders on and after 5 August in Manila.
and
Page 238 (257 of PDF file)

subordinate commanders of ComPhibsPac indicated possible
uses for up to 200 MBT's in the invasion of Sothern Japan.
ComMTBRonsPac was drawing up plans for such operations when
the war ended.

(b) Forces available.
The forces available to ComMTBRonsPac during the
period from May to August 1945 numbered about 275 MTB's,
which included a twelve-boat squadron that was en-route
from Panama at war's end.•• Of these the SEVENTH Fleet
operated 211 MTB's, including; some 50 boats that were too
old to undergo an arduous operation.

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Re: Army Sea Raiding Battalions

#12

Post by ChristopherPerrien » 05 Jan 2015, 23:08

The coastal nests within the zones/range of the landing beaches that these suicide boats operated out of would have been mostly obliterated by bombing and shelling. Be difficult to camouflage a base or nest of any size that had to sit on the coastline. I assume these boats might be able to be carried and launched by truck, but driving a truck or 50 or 200 trucks onto an invasion beach or nearby , would hardly be unnoticed, and just be something else blatant for NGS/ air-support to shoot at, if they are not shooting at the area to begin with.

Also there is the issue that every landing craft itself was armed with 2+ 30-50 cal machine guns, going up to several 20-40mm automatic cannons on LCI/LCT and LST size landing craft. Add on the Amtrack and Amtank armaments which could fire while floating , plus many dedicated/converted LCI to LCI(g) gunboats plus close-in and flanking destroyers, a US ship-to shore- invasion force in the Pacific of 1945 was literally bristling with mgs, auto-cannons, cannons for shoreline ops and AA defence, waiting and ready and itching to shoot at any threats. Then they are the waves of close support air-craft flying in and out to hit shore targets.

Looking at these boats, one 50 cal would shred one at in a manner of seconds at 1000 yards. They aren't aircraft kamikazes, so they are moving relatively "slow" even at best 40-50 knots, and are I assume un-armored(even if armored to an maximum extent (10-20mm), that would not stop a 50). . A 30cal could dice one in a few seconds at 700-300m. I am looking at the vital target area of engine-controls-pilot-bomb, discounting any possible sinkage/stoppage caused by 10 -30 "leaks" as the thing might have a PTO bilge pump. Using my experience of shooting 30's, 50's from a moving tank :milwink: Granted shooting floating targets at sea is slightly more difficult because range is harder to judge. Have done this too. The heavier weapons- 20mm 40mm,3in, 5in, would just be "un-fair".

So give the Japanese several hundred or a 1000 of these speed boats with a minimally trained "sailor" and a quite exposed 500lb bomb/self-destruction device , within an invasion area or capable of reaching it , 80-90% will be destroyed before the invasion waves start, the remaining 100 or so will face a hurricane of fire(that will/was probably never be equalled again in warfare) from the time they attempt launch to the time they could ram a ship or boat. Maybe 1 or 2 might hit something, and there is going to be no disruption of import, to a landing force of literally 1000's of armed landing craft, LVT's, boats, and ships, manned by many very experienced veterans.

Eggshells at a wall, though a storm of fire..

And try a few 100 at night , given US Radar/ gunnery and expertise/experience by then, again 1-2 might get through.

Whether the USN has 50 or 200 MBT's on station, they are only going add a little more to the storm of fire already present.

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Re: Army Sea Raiding Battalions

#13

Post by Wellgunde » 06 Jan 2015, 03:32

Fontessa, thank you for the CO info.
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Re: Army Sea Raiding Battalions

#14

Post by flakbait » 06 Jan 2015, 12:31

Agree with them facing an all but righteous fire storm while probably from the time they were assembling and sortieing out as well during there run in towards their targets. would imagine they might attempt to counter using darkness and/ or bad weather as well as coastal features to attempt to "mask" their approaches when ever possible. And while the USN historically ultimately learned to deal with every tactic and technology Imperial Japan could muster it was a very steep and costly "learning curve" on occasion...there is a difference between dealing with even a dozen suicide motor boats and engaging possibly as many as 100 or even more in a single wave. The same principle held true of the Kamikazes; throw enough of them into an attack and simply attempt to get as many thru as possible and dilute and overwhelm the defenders; it certainly didn`t always work, but there WERE those thankfully few God awful moments that it DID. Again agree that the vast majority of them are going to be rapidly destroyed...btw, enjoyed listening to "Ma Deuce" bark out bursts and sending tracers down range too.

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Re: Army Sea Raiding Battalions

#15

Post by Mil-tech Bard » 06 Jan 2015, 18:20

The Japanese small boat threat at night was rather large as the SO-7/SO-12 radars of PT's and LCI/LSM gunboats could only pick up the suicide boats at a few thousand yards less than half the time and the DD/DE SG radar was less effective than the SO because it had to stand father from shore due to their deeper draft hulls.

The following are passages are from an unpublished paper titled "Industrial Scale Asymmetric Warfare" by Donald Chisholm of the US Naval War College, with the first passage on a “Flycatcher Patrol” off Okinawa in May 1945 to stop suicide boat, AKA "Skunk," raids --
Operation Iceberg had begun its second month. The night of 3 May, LSM-5, Lt. Arthur S. Henderson, USNR, was patrolling in Nakagusuku Wan (shortly renamed Buckner Bay) on the east side of Okinawa, between Chinen Saki and Kuba Saki. There was no moon; the sky was in broken overcast. A faint breeze rippled the water. Visibility was good. At dusk Henderson had set a Condition II watch. Since then all had been peaceful.

Shortly after 2300, word was received from CTU 51.19.5 that a possible Japanese boat had been spotted to the south, steering a northerly course. At 2305, not one but two boats were sighted only 350 yards away, bearing 210 degrees true. Captain Henderson sounded general quarters and stopped all engines. Both boats attempted to cross the ship’s bow from starboard to port.

Suddenly, two more boats loomed in the darkness, these only 150 yards distant. Using its signal lamps, the LSM illuminated one to port and one to starboard, effectively blinding their coxswains. The starboard boat commenced a direct run on the ship, which opened with those of its 20MM cannon and .50-caliber machine guns that would bear. The boat exploded violently only 50 yards away. Simultaneously, the port-side boat ran parallel to and opposite the ships head at about 100 yards distance. The port gunners quickly set it afire with incendiary rounds.

Now the signalmen turned their lights to the remaining boats. One had already gone out of range, the other had apparently sunk. The brief, violent episode over, the LSM returned to its patrol. At 0019 another enemy boat was spotted at 170 degrees true. At just over steerage way, the ship turned to close the target. The boat’s coxswain abruptly accelerated in an effort to crash the LSM’s port bow. Although he managed to close beneath the bow 40MM’s depression angle, two .50-cal gunners set the boat on fire. It drifted to within 50 feet of the ship’s port quarter and blew up, showering Henderson and his crew with debris.

Again, the amphib resumed its patrol. About 90 minutes later, still another boat was spotted, this time by the ship’s surface search radar. Henderson closed the target and set it afire with two short bursts from the 40MM. This boat burned to the water, but did not explode.

The evening’s excitement was not yet over. Shortly before 0300, near the northern end of its patrol run, the LSM sighted another boat at 245 degrees true off the starboard bow. Henderson first turned his ship directly toward the target and then swung hard to port to uncover his starboard guns. The signalmen illuminated the target and the gunners commenced firing. The boat increased speed and drove toward the LSM’s stern. The 40MM fired as long as it could bear, the after guns until they were blocked by the stern. During a brief lull in the firing, the enemy craft exploded in a dense cloud of black smoke.

The remainder of the night’s patrol proved uneventful and tired captain and crew greeted the dawn. Now their day job — lightering equipment and supplies from the larger ships to the beaches — would begin. So too would the threat of attack by Kamikazes. At a cost of 384 40MM, 800 20MM, and 3,210 .50-caliber rounds, LSM-5 had destroyed five Japanese boats, with one other possibly sunk, all in less than four hours.

The LSM-5 had not been the intended victim of the Japanese boats. Rather, they had been ordered to attack the amphibious shipping of Task Group 51.19 — transports, cargo ships, landing ships, and the like — which were anchored in loose formation in the center of the bay. However, the LSM was precisely where it was supposed to be and doing what it was supposed to be doing. It, along with a number of other small amphibs and combatants, was on “flycatcher” patrol, established to intercept and destroy any suicide boats or swimmers sent by the enemy to attack the amphibious shipping in the bay.
The Japanese were well aware of the daytime limitations of the IJN Shinyo and IJA Renrakutei small boats.
...The TH 150-cm radar, whose ring parallel wire transmitter had a peak output of 13 kW, was intended for shore installation near points on the Home Islands (it weighed 500 kg.) where the Japanese expected landings by the Americans. Capable of detecting small surface ships (as well as the Shinyo boats) at distances up to 20 kilometers, the TH radar was to be used to locate targets and then to guide the Type 8 squadron leaders and Type 5 division leaders to them by radio.

U.S. Naval Technical Mission to Japan, “Target Report — Japanese Experimental Radar (Intelligence Target E12 of Fascicle E-1),” December 1945, microfilm (Wilmington, Delaware: Scholarly Resources). See also http://www.star-games.com/exhibits/japa ... radar.html.
THE US Navy had some knowledge of this TH small boat guidance effort, likely via Ultra code breaking, as they were looking at Japanese radar activity on Okinawa to see if it was guiding Japanese small boat attacks there.

The key thing about the TH was that it was operating in the same frequency bands as the US Navy SC and SK air search radars. This prevented heavy jamming of the TH by the US Navy.

and also see --

It was intended that the Shinyo Type 5 boats would lead their divisions of Type 1 boats (by visual contact, as the latter had no radios) from their bases to the immediate vicinity of the American transports. The boats were then to operate as tactically-coordinated pairs, the thought being that if two boats attacked a single target they might defeat the defender’s ability to maneuver, if under way, or to accurately fire on the attacking boats. One boat was to attack each side of the target. Presumably one boat might miss, be sunk, or be deflected by its target, but the other would get through. Recently, in an analysis of the contemporary small boat threat to littoral operations, Hughes has termed this exact approach to small boat attacks as “swarming.” As we shall see, it was a wise decision by the Japanese.

Once near enough to their target to be confident of their aim, they were to accelerate to full speed, and, in the case of the Shinyo, crash directly into the unlucky ship, or, in the case of the Renrakutei, approach near enough to loose their one (or two) depth charge(s). The Navy’s boat crews were instructed to aim at the after one-third of their targets in order, presumably, to effect the most lethal damage by hitting the engineering spaces.

By the time of the Okinawa operation in spring 1945, the Army’s Renrakutei were directed to attack in numbers of one to three to a target ship. A typical three-boat attack called for all three approaching from astern, with the lead boat laying its depth charge(s) well forward alongside the ship, the remain two dropping their charge(s) at vital points further aft. Alternatively, according to an Army manual of early 1945, three boats might attack from one side of a ship, with one forward, one amidships, and one aft. A two-boat attack would also come from astern with each boat laying its charge(s) approximately amidships. Single-boat attacks could come from ahead or astern. Navy Shinyo tactics, as revealed by American observations of their attacks, appear to have been roughly like those of the Army’s, but are not otherwise documented. No similar documents exist for the Navy’s boats, but American action reports indicate that they were comparable to the Army’s, although their smaller operational numbers mostly precluded swarming attacks.

72 Wayne Hughes, “How to Take the Small Boat Threat Seriously.” A Contribution to the Small Boat Threat Workshop, Office of Naval Intelligence, Suitland, Maryland, 16-17 May 2000.

73 O’Neill (1982), p. 113 (chart).
I ran down this article researching the foot notes of a US Navy article on how to counter Iranian boat swarm attacks.

The one real limitation of Prof Chisholm's article and the Richard O’Neill's book, [Suicide Squads: W.W. II: Axis and Allied Special Attack Weapons of World War II: Their Development and Their Missions (New York: St. Martin’s Press, 1982)], that Chisholm drew upon heavily in the article on was that neither used the well documented anti-suicide boat work done by the US Army Engineer Special Brigades in the Southern Philippines.

After Okinawa the DD captains didn't want to do the anti-small boat mission and there were not going to be enough dual hatted LCI/LSM because of the aerial Kamikaze threat in daylight.

As PT boats had actually dodged several Kamikaze attacks in daylight supporting the West Leyte landing operations by the 77th Division -- one PT was attacked 3 times in 10 minutes and all three attackers missed! -- it was a far better platform for Renrakutei/Shinyo hunting off of Kyushu.

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