The Search for the Grunion Blog

As we mark the anniversary of the loss of USS Grunion (SS-216) on July 30, 2011, let us pause to remember our 70 brave and valiant men who paid the ultimate price 69 years ago.

We Remember Them
(By Sylvia Kamens and Jack Riemer)

In the rising of the sun and in its going down,
We remember them.
In the blowing of the wind and in the chill of winter
We remember them.
In the opening of the buds and in the rebirth of spring,
We remember them.
In the blueness of the sky and in the warmth of summer,
We remember them.
In the rustling of the leaves and in the beauty of autumn,
We remember them.
In the beginning of the year and when it ends,
We remember them.
When we are weary and in need of strength,
We remember them.
When we are lost and sick at heart,
We remember them.
When we have joys we yearn to share,
We remember them.
So long as we live, they too shall live,
For they are now a part of us,
As we remember them.

On February 16th Chiyo was 100. She received a number cards and gifts from the Grunion Family. This is her son’s Kazuo’s reply.

Dear Bruce John and Susan Abele, Mary and Dick Bentz and each of the family of USS Grunion,

Thank you for your wonderful presents on my mother’s 100th birthday.

She is deeply very moved to receive blessing from a lot of people, because the tradition of sending the birthday card like this is few in Japan, though the New Year’s card is sent.
She becomes physically handicapped recently, spends the life indebted to an around person, and is leaking it to husband’s place to pass away early. She often spends in the special nursing home for the aged.

However, meals are taken regularly though it is few. She sometimes reads newspapers and books. It is happy time when she spends with six-year-old great-grandchild “Aiko”, kindergarten girl. She helps for her great-grandma to move in the room. (See photo.)
I think that the family of the fourth generation is comfortable for her.

The hearty birthday congratulation was unexpectedly received at such time, and her mind became very satisfiable. She says that she wants to dedicate the
mind of the sorrow to the bereaved family of the same circumstances as her from 26 postcards .

The congratulation on 100 years old will be brought from the city office on February 16, and a TV Producer will come to cover. I hear Yutaka will visit to bless.
My sister, brother and I, our three couples will welcome them.

It prays for the good luck of everybody.

Sincerely yours,
Kazuo Shinoda for my mother, Chiyo
(Please forgive my poor English. )

———-

Also please see:

Torn apart by war, united by gifts of flowers

KISKA PETALS- “I send flowers of this place to you with my heart.”

Though, Mr. Shinoda did his best and achieved his ordered mission. Even though the war was not the crusade, above is the situation of those days. I suppose now they both friend and foe alike at the north sea under falling ice, must be hoping the peace and reconstruction of home country, also praying the fortune of families, smiling how we were so unwise that fought such war.

Bruce abele@999info.net

Per United States Army regulations, the Purple Heart is awarded in the name of the President of the United States to any member of the Armed Forces of the United States who, while serving under competent authority in any capacity with one of the U.S. Armed Services after April 5, 1917, has been wounded or killed, or who has died after being wounded. Accordingly, every member of the crew of the USS Grunion should have received a Purple Heart.

They did not.

Back in December 2009 Dick and Mary Bentz spent a week at the National Personnel Records Center in St. Louis getting copies of the personnel records of the Grunion crew. That’s when they discovered that although the enlisted crew had received that medal, the officers had not. The Abele family had thought that their Purple Heart had been somehow misplaced and there had been an ongoing search for a number of years.

Almost immediately Mary notified the appropriate authority and was assured that the situation would be corrected.

In March 2010 nothing had happened so Mary went up one step in the hierarchy and this time was informed that even though she had provided them with proof, it would take three months to reprove that Purple Hearts had not been received by any of the officers. After that there would be a six-month wait while they determine whether the officers deserved Purple Heart even though all enlisted men on the Grunion had received them.

Next step, while at the Purple Heart Hall of Honor Mary discovered that in these types of situations you contact the Chief of Naval Operations. On her suggestion I wrote a letter to that individual. Within about three weeks we had the Purple Hearts.

It seems to me that when we ask our young men to fight and possibly die for our country, our country has an obligation and duty not to forget. Presenting the Purple Heart 68 years later turns out to be a form of that remembering. Unfortunately there are some people in responsible govermental positions who do not understand nor care about that responsibility

Mary Bentz

Sixty eight years ago today the USS Grunion left us forever. Her memory remains with us and we continue to remember and honor those 70 men who paid the ultimate price that day.

Taking place this afternoon at the Veterans Cemetery in Jacksonville, Missouri there is a memorial service for USS Grunion’s Electrician’s Mate Third Class, Ernest Glenn Hellensmith from Moberly Missouri, arranged by his niece, Becky Franke. Just a few weeks ago, one of the finest tributes to this Grunion crew member and the USS Grunion, appeared in the Moberly Monitor by Ben Herrold, and can be found at Lost Found and Remembered.

During the past year, my main focus has been honoring each of our crew, at many military web sites, including those listed below. This labor of love continues. We encourage you to visit the following sites regularly.

On Eternal Patrol

Created and managed by Charles Hinman at the USS Bowfin Museum in Honolulu, the site continues to be updated and enhanced. Just this year he has completed personal memorial pages for each of the over 4,000 men lost while serving in the U.S. Submarine Force since 1900. He is also heavily involved with the five lost submarine discoveries in the last five years.

The Navy Log

This monumental task began a few months ago. I have had the distinct honor and pleasure to be working with Ms. Nan McComber and her team in the Navy Log Department at the Navy Memorial in Washington, D.C. All 70 crew members’ logs already existed on the Navy Log., but during the past several weeks I have worked with Nan to update the crew information acquired from each of the crew member’s Service Records.

Her excellent work, her outstanding ethics and devotion to the men and women who have paid the ultimate price, is commendable. She and others in her department have worked long days, into the evenings and weekends to reach this goal. Completed just today are these updated logs for each of the crew to include Photos and Significant Duty Stations.

When the Navy Log site appears, insert USS GRUNION in the duty station and click on “Find it.”

Find your loved one’s name on the list and click on “view log” If you want to look at other crew member’s logs, use your “Back” to take you back to the complete list of crew members.

At the bottom of the page there is a reference to “Memories”. This is another part of the Navy memorial Log that I will be working on with Nan in the near future. If you have special memories that you would like for me to include, please email me at ca.par@hotmail.com and I will do my best to accommodate your wishes.

This website also presents a “Ship’s Tribute” site which provide tributes to all of the ships that served in the Pacific. Grunion’s site was just completed this week:
United States Navy Memorial

The Purple Heart Hall of Honor

The National Purple Heart Hall of Honor commemorates the extraordinary sacrifices of America’s servicemen and servicewomen who were killed or wounded in combat. The mission of the Hall of Honor is to collect and preserve the stories of Purple Heart recipients from all branches of service and across generations to ensure that all recipients are represented.

Working with Alison Manges and Bobby Montarro is a very pleasant experience and all of our men, with the exception of the officers of Grunion are now enrolled here. Grunion’s officers who as a group are not only unlisted on ABMC as Purple Heart recipients, but who were, it seems, never “put in” for the medal. We are continuing to work with Navy Casualty to have these medals awarded and forwarded to the officers’ next of kin. We will also continue to work with Navy Causality to correct all errors that we find.
The Purple Heart Hall of Honor is located at 374 Temple Hill Road, Vails Gate, New York. If you are in the area please consider a visit to this Hall of Honor in your plans. It is a wonderful place to learn about history of our brave veterans. Their displays tell a story that needs to be heard by all Americans. This facility provides a wonderful history and a memorial to those who gave of themselves.
The Roll of Honor is accessed by http://www.thepurpleheart.com/recipient/. Follow the prompts to reach the Roll of Honor.

If you know of any other Purple Heart recipients, check with Alison Manges alison.manges@oprhp.state.ny.us to verify their enrollment in the Purple Heart Hall of Honor. She will be happy to help.

WW II Registry

In the January 28, 2010 Grunion Blog Update we talked about the WWII Registry. Let me review what is available there:

The Registry is a wonderful tool that combines four distinct databases that can be searched for names of those whose service and sacrifice helped win the Second World War. Those listed are on official War and Navy Department Killed in Service rosters now held by the National Archives and Records Administration (NARA). Also there is an opportunity for the public to enroll any and as many Registry of Remembrances as desired. Note that:

• For each of the USS Grunion crew, there is a tribute and a photograph from “The Families of the Grunion”.

• The United States Submarine Veterans, Inc. has permitted me to update each of the Grunion crew files. That was completed early spring this year.

One of the four databases in the WWII Registry, ABMC Tablets of the Missing has a link for each of our men. There is also a link on their own website. Many others and I have found it to be riddled with errors, and began contacting them last December. I have been trying to have the worst of the errors corrected, but there are a number of corrections that have not been taken care of. In seeking assistance from the Navy POW/MIA/KIA Casualty Assistance Branch in Millington, TN, and forwarding evidence to support our claims, we were able to get some relief. But errors are still there and I have no idea when to expect updates.

ACKNOWLEGEMENTS

With the exception of the eye witness accounts and other documentation that came from historians in Japan, most of the historical information we have about the USS Grunion has been obtained with the able assistance and guidance of personnel at the offices the National Archives and Records Administration (NARA) in both Washington, DC and College Park, MD, and at the National Personnel Records Center in St. Louis, MO. The Personnel Records, Purple Heart Cards, Muster Rolls and Change Reports, Deck Logs, Log Books, and War Diaries provided by these facilities have made it possible to follow the Grunion’s keel-laying, her construction, her commissioning, her journey and experiences on the way to Pearl Harbor, her training in the Pacific, her first and only war patrol to the Aleutian Islands, and the background of the valiant crew of 70 sailors who were lost when the Grunion went down.

The following are to be commended for their eagerness and dedication to remembering, honoring and respecting all of our fallen Americans. The focus and goal here is to make this history accurate for not only those who want to remember now, but in coming years as new generations reach out to learn about and remember these heroes. Research matters.

National Archives and Records Administration:
• Steve Riordan, McCaffery Associates
• Pat Osborn and Nate Patch - NARA, College Park, MD
• Whitney Mahar and Christopher Secrest, National Personnel Records Center, St. Louis, MO
• Paul W. Wittmer, WWII submarine veteran and dedicated volunteer researcher in St. Louis, MO

Kenneth Terry and Rudy Gonzales of the POW/MIA/KIA Branch of the Navy Personnel Command, Casualty Assistance Division in Millington, TN are working toward having the corrections made at ABMC. They are also working to have Purple Hearts awarded to the seven of Grunion’s crew (6 officers and one enlisted man) who did not receive them.

Thank you all for making this possible.

If you have any questions, or find any errors or discrepancies in the links, please don’t hesitate to contact me.

On this day of remembrance, I would like to share this poem which was sung on the 50th anniversary of the Liberation of the Camps. Dick and I were honored to be a part of the choir that sang it at Auschwitz that day.

We Remember Them
In the rising of the sun and in its going down,
We remember them.
In the blowing of the wind and in the chill of winter
We remember them.
In the opening of the buds and in the rebirth of spring,
We remember them.
In the blueness of the sky and in the warmth of summer,
We remember them.
In the rustling of the leaves and in the beauty of autumn,
We remember them.
In the beginning of the year and when it ends,
We remember them.
When we are weary and in need of strength,
We remember them.
When we are lost and sick at heart,
We remember them.
When we have joys we yearn to share,
We remember them.
So long as we live, they too shall live,
For they are now a part of us,
As we remember them.

Bruce mbabele@999info.net

It has been 2 1/2 years since the ROV trip. Now, due to an unusual sequence of events, we have been provided some insights that may add significantly to our understanding of the Grunion loss.

I want to introduce to you 87-year-old Cmdr Charlie Tate. Charlie has a background uniquely suited to understanding the elements of the confrontation between the Grunion and the Kano Maru. He started the beginning of World War II on a cargo ship (same tonnage as the Kano Maru) moving material to Dutch Harbor. Around 1943 he joined the USS Gato and eventually became the chief of that sub. When he was 11 he earned money by dynamiting stumps which he then hauled, by donkey, to the Hercules Dynamite factory. The significance of what he learned from that dynamite experience will show up later. His words:

I in no way consider myself the best authority on submarine warfare however I have observed, conducted, evaluated, and or participated in literally dozens of torpedo approaches in war and peace time. With absolutely no input from Grunion and conflicting information from Japanese sources other plans may be offered. My comments are offered only as another possibility as to what could have occurred

What Charlie brings to the table is the ability to study current thinking and point out aspects that are inconsistent with his experience. He has spent considerable time reviewing John Fakan’s anaglyph photos and analyzing the confrontational path suggested in current thinking.

Point 1. Current thinking on the path of the two vessels puts the Grunion ending up south of the Kano Maru in a position where escape would be hampered by McArthur’s Reef. He argues that would never have happened. The Grunion started off in a excellent position and it would be ludicrous to move away from that area. A torpedo attack is a carefully planned operation. CT’s words:

When a target is sighted the Contact Phase of a torpedo attack begins. The direction of the relative movement of the target must be determined and it is accomplished by observing the angles on the bow or by heading towards the target and observing the direction of bearing movement. The duration of this procedure usually takes about five minutes to gather the information required. The next procedure is the Approach Phase or to maneuver aggressively and tenaciously to close the target range to the best position to commence the Attack Phase. This position will be relative to the enemy and will vary depending on sea condition, detection devices in use by target, speed of target, course of target, presence of air or sea escorts, or target tactics( zig-zag). The target had none or was not using any of these diversionary devices. We are now at the firing point to start the Attack Phase. Grunion Conning Officer(CON), the commanding officer when at Battle Stations, made the last quick look to add final visual input to the firing solution to verify that sonar, Torpedo Data(TDC), and visual were all in agreement. If they were the order to fire was given; “fire one“, five seconds later, “fire two. and the torpedo run time to target is reported to CON. Sonar would report No1 hot straight and normal, then No2 hot straight and normal. At the expiration of run time CON would “up scope” to witness the hit and report any change in angle on the bow. In this case one torpedo stopped the screws of the target and sonar would have reported “screw count zero” meaning the screws were no longer turning. If the target was firing deck guns any “Shots “ would be seen, any fairly close hits would be heard by sonar and if close enough also by ear. The TDC would have continued the solution progressing from last data received. A quick look would have seen the drastic change of angle on the bow, sonar reports no appreciable change in bearing, or range, and advance target track line was minuscule, all verifying that target was dead in the water. Grunion was probably considering reloading at least the two upper torpedo tubes for the target was still afloat.

Point 2 He argues that the Kano Maru then drifted not west but in a clockwise manner and because there was neither land nor wave reference that the crew of the Kano Maru mistook the movements of the Grunion for movements of their own ship. Charlie’s words

The Kano Maru was south of Grunion on a westerly course at a speed of 15 knots. She reported that the torpedo tracks were sighted approaching forward of her starboard beam. She immediately applied hard right rudder and turned toward Grunion to split the track and also present a silhouette vice a broad side target. Standard steering systems are a movement on order device and the rudder would remain in its last position until ordered otherwise. When the torpedo struck in her machinery space she lost propulsion power, and steering. With the momentum of 15 knots and hard right rudder applied means she will circle continuously to starboard until losing momentum. The distance of travel is estimated to be 1200/1500 yards. She is firing her deck guns haphazardly at what she thinks is a moving submarine periscope. Grunion knew immediately from two sonar systems that target screws had stopped and she was going nowhere. Kano-Maru had four more torpedoes fired (three duds) at her from different relative bearings making her believe Grunion was moving extensively and not realizing that her own circling movement was responsible for the bearing changes.

It was also known that Kiska could hear gunfire and that aircraft were based there. The thought of going to Battle Surface to finish off the Kano Maru was not seriously considered for this meant opening hatches and exposing at least ten men on deck. Visibility was restricted which would give aircraft the advantage of getting very close before detection. A small hole in the pressure hull could be disastrous or the loss of ten men in a forced dive was just not worth the risk. Four more torpedoes were fired in this attack, one passed under starboard bow, three more at portside. Grunion had no reason to maneuver excessively to remain in firing position for the last four shots as no evasive movements were required. The target was slowly moving with no propeller noise so all Grunion had to do was remain at firing range and keep her bow pointing in the general direction of target.

Point 3 Charle’s third point: There was never a broach. The Kano Maru was shooting at the wave caused by a massive bubble when the Grunion imploded. His words:

Kano Maru reported seeing rolling of the water like a submarine surfacing and fired at it with her deck gun then immediately seeing a huge eruption and a column of oil spraying into the air. This could not have been caused by damaging the periscope shears. There is absolutely no vital machinery, piping, fuel tanks, air systems, hydraulic systems or anything else in the conning tower area that could cause fuel and air to spurt like reported. Whatever caused this commotion had to be the eruption of fuel oil tanks.

Jon Britton pointed out a long time ago that with the shears above water there is no wake just a ripple. See http://999info.net/Grunion/AttackInfo.pdf about 3/4 of the way down.

Point 4: The damage to the shears was so extensive that it could not possibly have been caused by a 3 inch shell a shell that contains the equivalent of 1 ½ pounds of dynamite. The shell weighs 17 lb and travels 2700 ft sec. Because it is designed for aircraft when it explodes that linear momentum is transformed into spherical momentum, something like a hand grenade. Charlie:

Photographs of the aft upper shears show severe damage that might be caused by a heavy fast moving mass. They were pushed forward bending the shears lifting up the deck and shearing off the connecting bolts. What could have caused this? A circular running torpedo possibly. Malfunctioning torpedoes were prevalent at this stage of WWII. Inconsistent depth control, malfunctioning exploders resulting in duds, and the dreaded circular running torpedo were reported in a very high percentage of firings.

Point 5 This is a slight variation on earlier thinking. Note that the USS Gato had experienced a locked rear dive plane. CTs words:

Grunion was at periscope depth (shears 16 ft down) deciding how to finish off the Kano Maru when something smashed into her shears. The damage was extensive and very loud, it shook the boat but watertight integrity was not breached. The CO knew no surface ships were in the vicinity and the Kano Maru deck gun was no threat so the logical deduction was an aircraft had sighted him at periscope depth and dropped a bomb. In anticipation of another bomb he made the decision to “take her down” to a deeper depth. This not a normal change of depth order to the diving officer. This “take her down” order means as quickly as possible. Bow and stern planes are placed on full dive, all full ahead is ordered, negative tank is flooded, and a steeper than usual down angle is ordered. Negative tank holds 20,000 lbs of water and that destroys neutral buoyancy instantly, the planes tilt the boats bow down, full speed on the propellers drive her down. At about 65 feet negative is blown dry. This takes about 15 seconds. With negative empty neutral buoyancy is restored. But speed and angle are still driving the boat down. We are now passing 100 feet. Full rise on bow and stern planes is ordered. All ahead 1/3 is ordered. Normally this will allow the boat to level and the descent can be stopped around 150 feet. However if something goes wrong, like the stern planes lock on full dive, emergency measures must be applied INSTANTLY. If the down angle reaches 30 degrees, all back full is ordered and all main ballast tanks are blown. A down angle of 30 degrees or more makes it very difficult for men to remain in position so they can perform their duties. When “blow main ballast” is ordered the man on the high pressure air manifold has eight or more valves (depending on fuel on board) to open by hand [and they require a handle (which could be dropped] and must be opened rapidly in order(1-8) to bring the bow up. If the controller man on speed control gets thrown out of position and can’t answer all back full. Disaster. Grunion had a test depth of 300 feet an out of control dive can reach that depth very quickly.

The last torpedo Grunion fired was a miss and it could have made a circular run and hit the shears. The time frame allows this.

Several witnesses reported seeing a black rod shoot up and then fall back. Approximately 15 foot of the torpedo is a container that holds 3000 pound air used for powering. When empty that container would float and it is coated with a black glop. That may have been the black rod that shot up and then fell back.

If the circular run hypothesis holds up considering that a dud torpedo hit the small profile of the Grunion it creates an almost unimaginable end to this story.

Charlie presents some rather dramatic and interesting changes in the thinking about the loss. However like all of these hypotheses we need to aggressively search for inconsistencies or we can believe almost anything

Comments please.

Some Additional Information

First Some Philosophical Ramifications

Imagine there is a small fire. Somebody picks up a container of gasoline and tosses it on the fire and lo and behold the fire is extinguished. If you observed this there would be a double take. This is NOT consistent with experience. You cannot put out fire with gasoline.

One other bit of supporting consistency. If you look at Jon Briton’s Attack info (999info.net>Grunion>Attack Info.pdf about ¾ of the way down) you will see what shears create as a wave, It is a ripple not a washing wave. A washing wave is what you see at the beach or what is created when a large amount of water is disturbed for example when a massive bubble rises to the surface.

Some Specifics About the Charles Tate Hypothesis

If the Tate hypothesis is determined to have credibility it adds a great deal to the understanding of loss of the Grunion. I want to summarize below the elemental hypotheses behind it.

I think that it’s easier to understand if we work backward in time.

1. There is general agreement (from studying John Fakan’s 3d anaglyph photos) that whatever damaged the shears came in over the stern. Charlie Tate hypothesizes that a 3 inch shell could not possibly create that much damage particularly when the shears were almost certainly 16 feet below the surface. (See Status Report 2/11 blog entry below) Charlie’s background is unique for that understanding having worked with dynamite as a youngster and having used a gun almost identical to that on the Kano Maru many many times. To help support his hypothesis he presents a photo of the shears of the USS Torsk which was rammed by an approximately 2200 ton destroyer. The damage is similar to that of the Grunion. However, the momentum is dramatically different than that from a 3 inch shell. Study the photo below carefully

2. Recognizing that the Grunion was almost certainly at periscope depth by process of elimination about the only thing that could cause that amount of damage would be a circular run DUD torpedo. A bomb or an exploding torpedo would have created much more damage and a mine is very unlikely.

3. Some will suggest that the sub had broached or was surfacing. The evidence behind that is from Aiura’s report. There are several translations of that report two of which indicate LARGE amounts of oil. That oil could only come from the fuel ballast tanks 45 feet down. They could not have been damaged by a 3 inch shell. I think it’s safe to say that none of the translations indicate a positive clear cut recognition of a surfacing submarine. I have copied the pertinent parts of those four translations below. Bottom line, what was observed was a massive bubble from the imploding sub.

• Vern Miller translation: Time: 0610 hrs. Kano Maru again saw the periscope at a range of 400 meters (135° left) and again opened fire with her cannon and machine guns. The periscope at this time approached Kano Maru’s stern and began to surface slightly so that what seemed to be the top of the conning tower, making a wake, was visible. One 8 cm shell hit the tower. Water splashed up with a dull explosion and much oil erupted from the top of the tower [3]. This was the 84th shell fired by Kano Maru. The Japanese crew yelled Bansai”

• Unknown translation: 0610 A periscope of this attacking submarine was sighted 135 degrees port, 400 meters away from the ship. The Kano commenced firing 8cm guns and 13 MGs at below the periscope. They confirmed direct hits and exploding sound and tremendous amount of dark brown liquid was flushing out from the sea.

• Howland translation: At 0610 we once again got the periscope in our sights at 135 degrees left, at a distance of about 400 meters. The 8cm and 13mm guns on the front deck once again commenced firing. The enemy sub, with its periscope visible, lazily floated past the damaged Kano Maru, as if mocking us. This was most infuriating indeed. Then the sub began to surface, and ripples appeared around what looked like the control tower. Having been unable to sink us with torpedoes (loading up spare torpedoes at this point would have taken a good deal of time), were they now going to try to finish us off with guns? Or were they simply grossly underestimating us?It was at this moment that an 8cm bullet struck the submerged area of the enemy sub. Spray and the dull thud of an underwater explosion followed, as well as a swell of heavy oil. Once we realized that we had indeed sunk the sub, the entire crew gave a ‘banzai’ yell of triumph.

• Yutaka translation: 06:10 Then we find the periscope at left 13 5 degree about 400m distance. Our forecastle 8cm gun and 13mm machine gun again started the fire. The sub kept the periscope up and moved calmly ignoring damaged KANO MARU. We clenched our fists but had no way to do. [*3] Then the sub seemed to begin to surface. The conning tower made ripple on the surface and the wave began washing the conning tower. I think the sub was unable to sink KANO MARU by the torpedo ( reload the stocked torpedo to the tube needs much minutes ) so finish KANO MARU by its gun or the sub thought KANO MARU could do no harm any more. Just then a 8cm gun shot hit the washing wave, made water column and dull water explosion sound. Also we saw the swell of heavy oil. All crews shout ‘BANZAI

4 There is general agreement that the Grunion lost depth control as result of a jammed stern dive plane. (It happened to the Gato) In theory it’s possible to recover from such a situation by blowing the bow ballast and other tanks. However when the torpedo hit the shears it almost certainly caused severe disruption on the boat. There are a number of ballast tanks that need to be blown IMMEDIATELY and in a particular sequence. There is only one handle that fits onto each of the valves and if that was lost or dropped when the torpedo hit the shears it could have extended the time considerably. With a steep down angle one can reach crush depth very rapidly.

5 There is general agreement that the Grunion ended up pointing in a northerly direction (plus or minus 20 degrees) . For that to happen and to be hit by a circular dud torpedo coming in over the stern the target had to be southerly. (There is a some conflict here because the torpedo shot from the bow. The explanation is that the Grunion was trying to establish adequate distance 800 yds for additional shots). The explanation for the difference between Aiura’s path is that it was difficult to differentiate whether the Kano Maru was moving or the Grunion. See CT’s plot path below.