How many submarines did we lose in WW2?

We lost a total of 52 submarines from all causes or about 23%. We lost about 3,500 submarine sailors with their boats. This was the highest loss rate of any of the major American services during the war. (However, some of the smaller units, such as the Eighth Air Force over Europe, may have had a higher loss rate.) As bad as this loss rate was for our boats, most other countries in the war lost a higher percentage of their submarines

The most frequent cause of our submarine losses was enemy action, either to aircraft, anti-submarine warship attacks or a combination of the two. Some were lost to mines. Over the course of the war, four were lost when they ran aground on reefs although those crews were all rescued. At least two boats were lost when they were struck by their own torpedoes running in a circle, likely due to gyroscope failures. The first submarine we lost in WW2, the USS Sealion (SS-195), was struck by bombs while being it was repaired in the Philippines on one of the first days of the war. In a few cases, we don’t know why they were lost. It could have been enemy action, mines, torpedo circular runs or even operational errors, with no survivors to tell the story.

A few notes about unusual losses:

When the submarine USS Pompano (SS-181) was reported overdue, there was some confusion as to the name of the boat. It was sometimes reported in local papers as the Pampanito, which caused unnecessary grief for a few families until the error was corrected.

Two older boats, the USS Salmon (SS-182) and USS Halibut (SS-232) were so badly damaged that they had to be taken out of operational service. Salmon became a training boat. Halibut was just scrapped. However, they are not included in the count of 52 since they did make it home.

It has not been definitively established but the USS Dorado (SS-248) may have been sunk by one of our own PBM flying-boats when in a safe area. Other possible causes have been put forward as well but none have been substantiated.

The USS Corvina (SS-226) is the only U. S. boat known to have been sunk by a Japanese submarine. She was lost in November of 1943.

The USS Robalo (SS-273) was probably sunk by a mine in 1944. 77 men died in the sinking. Apparently, four others survived and were captured but died in captivity.

The USS Seawolf (SS-197) was sunk in late 1944 with 82 crewmen plus 17 U. S. Army personnel while en route to Samar. There was apparently a great deal of confusion in the area. In any case, Seawolf did not, or could not, respond to interrogation signals and was sunk by U. S. forces.

The summary of our submarine losses in WW2 is as follows: