An interesting description of what happened to an Israeli sub when it hit the bottom (2,900 meters) after experiencing an out-of-trim catastrophic hull failure.
The Dakar, imploded and broken up, continues her dive to the depths of the Mediterranean. Within 10-15 minuets she reaches the bottom of the sea and crashes with a huge impact. The crash separates the hull between the engine room and the stern compartment. This causes the broken stern to fly forward and land near the conning tower. Heavy parts fly in all directions,
(Unfortunately, the description is not from an official Israeli document. The sub was ex HMS Totem, commissioned in 1945, so maximum operating depth was apparently about 100 meters.)
All the oceanographic 'experts' badly missed the final position as well.
Search and Discovery of the Israeli Submarine Dakar
INS Dakar - Wikipedia, the free encyclopedia