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Question For Those With Knowledge..

posted 13 years ago by Monkeydigital
6 replies | jump to latest

I see quite a few of the posters here have either been in the Navy or have some intimate knowledge of submarines. Since I cant find the answer on the net, I will ask here. Just how did WW2 sub captains know how deep the water was below the boat? Meaning, how were they able to tell how close the boat was to running aground, especially in an engagement near costal waters or a harbor? I can almost gurantee that their have been instances where a sub has crash dived or dove to steeply and plowed into the ground below.

[–] michaelnewman01 13 years ago

1) Yes, plenty of submarines have run aground or hit the bottom of the sea during a dive. It was more common in that time, but has still been known to happen today.

2) I'm amazed you couldn't find anything. There are many ways to reasonably determine water depth: fathometer readings/soundings and charted depth, to name a couple. Of course, oftentimes charts were less than complete, especially in regards to enemy waters, but sub captains made do.

"You feel the way the boat moves? The sunlight on your skin? That’s real. Life is wonderful."

[–] Monkeydigital 13 years ago

Thank you so much for the reply. Im aware of navigational charts being available and utilized at the time, but in the 40's and earlier did the technology really accurately exist to determine with a good amount of certainty that distance to the ground below?

When I read some of the deployments from these subs from all the different nations, you have to wonder, how many actually dove to deep and imploded, crashed to the bottom or simply collided with other subs. I have just always had the utmost respect for the armed forces and anyone that had the balls to get inside of a steel cylinder and descend 100's of feet BELOW the surface of the water.

Either way, thank you for your response and your time. :)

[–] michaelnewman01 13 years ago

In general, the Pacific is a fairly deep ocean, so unless you were doing a harbor approach, you were generally in deep water. Determining ownship depth is usually straightforward since pressure increases pretty linearly with depth. Also, it is actually possible to bounce a fathometer ping off the surface to determine depth that way.

As for charts, even today they incorporate a considerable amount of guesswork. Even back then the technology was quite available to determine depth accurately, but surveys are very time-consuming. Open ocean charts are woefully incomplete, and you to this day have disasters like USS San Francisco running into an uncharted undersea mount. In once case during WWII, LT Richard O'Kane, XO and navigator on USS Wahoo, improvised a harbor chart using an illustration from a children's atlas.

As we say in the Navy, "use multiple means of fixing position."

In the case I cited above, Wahoo took down a Japanese destroyer with a down-the-throat shot in about a hundred feet of water. That's about as crazy as you get. You would do well to look it up. If you're interested in WWII Sub Warfare, I recommend Unrestricted Warfare by James DeRose.

As to how many submariners faced such trials, remember that the Submarine Force suffered the highest per capita KIA rate of any U.S. military arm in WWII. Around 33% of those who went to sea were killed.

"You feel the way the boat moves? The sunlight on your skin? That’s real. Life is wonderful."

[–] Monkeydigital 13 years ago

Awesome stuff Michael thank you! About to get to researching the USS San Francisco and the Wahoo right now. :)

[–] CGSailor 13 years ago

Damn... missed a good technical discussion!

dagnabbit!

I joined the Navy to see the world, only to discover the world is 2/3 water!

[–] CGSailor 12 years ago

Tow other books which discuss the Wahoo and her foray into a harbor armed only with an ad hoc chart are these...

"Clear the Bridge: The War Patrols of USS Tang"
Written by Dick O'Kane himself, he discusses the incident aboard Wahoo when he was the XO of that boat.

"Wahoo: The Patrols of America's most famous Submarine"
Also written by Dick O'Kane. Overall, not as detail oriented as Clear the Bridge, which puts you right in the action as though you were there... none-the-less it does [obviously] discuss the incident in greater detail than Clear the Bridge.

I joined the Navy to see the world, only to discover the world is 2/3 water!