Which submarine is noted for being the only successful rescue?

The USS Squalus is recognized for being the only submarine to successfully conduct a rescue operation after experiencing a critical failure while submerged. On May 23, 1939, the USS Squalus sank during a test dive off the coast of New Hampshire due to a mechanical failure. After the sinking, a daring rescue operation was launched, and using a salvage submarine named the USS Falcon, all but one of the crew members were successfully rescued from the sunken vessel.

This incident marked a significant moment in submarine rescue history, illustrating the effective use of technology and procedures in saving lives under extreme conditions. The successful recovery of crew members not only showcased the bravery and skill of the rescuers but also prompted advancements in submarine design and safety protocols in subsequent years.