Without knowing exactly what caused the Lagarto to sink, I can't give a 100 percent accurate opinion on this, but they probably didnt have much time to do alot. The Gulf of Thailand is really shallow. Shallow water amplifies depth charges, and makes the damage much worse to a submarine.
If they hit a mine, and it breached the pressure hull, it was probably all over in seconds. Sea pressure on the hull increases linearly with depth, and compounds flooding when a submarine is submerged. They would have had only a few seconds to escape, if even that, because a mine makes a pretty big hole in the hull.
Pressurizing a compartment with High pressure air would have bought more time, but as Travis mentioned, it probably would have been really hard on the crew-members doing it, if they even had the time to do it. In addition, it also would have made free-ascent impossible because the pressure in the compartment would have injured anyone trying to open a hatch facing outward.
They also could have been forced down until they suffocated, killed by poisonous Chlorine gas from a breached battery, suffocated by an onboard fire secondary to battle damage, or drowned by a breached hull valve that caused massive flooding. There are a million ways to die on a submarine. These are just a few
The Japanese also had a unique type of depth charge that consisted of a line, grapnel hook, and explosive device that traveled down the line to explode on contact with a submarine hull. Several boats described these in After action reports in this area of the world. it could be a candidate.
RE: #41
Great info, I've never heard of that Japanes anti-submarine mine before. Thanks
There are a lot of ways to die in a sub, not many are pleasant. But sometimes they did come to rest, mortally damaged, on the bottom. I'd rather take a chance with a Stenke Hood from 700 feet than die for sure in the sub.