When submarines were first developed, they had an awful reputation and for good reason.

There had been many accidents and many sailors whose graves were on the bottom of the ocean.

So much so that the submarine service had earned the nickname the Coffin Service.

In 1939, one of the worst of these incidents would add this reputation.

This is that horrifying story, and as always, viewer discretion is advised.

Between the end of World War I and the first shots of World War II, navies around the world

were tirelessly developing and testing submarine technology.

To that point, fighting a war under the seat was done by primitive means, but the early 1920s

marked a significant leap forward in submarine capabilities.

Countries race one another to build and deploy more advanced submarines capable

of diving deeper, faster, and for longer than ever before. Like other countries, the United States

invested heavily in bolstering its Navy with top-of-the-line state-art subs and in 1938, it launched

its class of Sargo ships, which were equipped with a new lead acid battery that was resistant

to battle damage.

One of these was known as the USS Squalus, which was one of the first in its class, and

was capable of reaching depths of up to 250 feet, surface speeds of up to 20 knots, and distances

of 11,000 miles on a single tank of fuel.

Even by the growing standards of submarine technology, the Squalas and its sister ship, the USS Sculpin,

were advanced beyond their years.

They had been designed in the lead-up to World War II for the task of cutting off Japanese

trade and could escape enemy planes by fully submerging in less than a minute while operating

at full speed, which was something that no other sub could do.

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