Bruce
Jim Christley has put together a sketch of the Grunion wreck that is rather amazing.
His annotations are listed below.

The numbers:
1. The general shape and size of the bow portion that is missing.
2. The forward bulkhead of the Forward Battery. I noticed that structural failure in this area took with it the structure in and around the torpedo loading hatch.
3. A major structural break which may have been caused by impact with the bottom.
4. The conning tower barrel with the reachrod type mechanisms for the helm. In later boats this was replaced by hydraulics, but the Grunion used electric planes and helm control.
5. A ‘debris’ or torn tankage area that deserves further study. I believe this is in way of a fuel tank and may point toward shell damage to the tank and possibly some internal piping.
6. Lines that indicate the the size of the pressure hull over the engine rooms.
7. A major hull break in way of the After Engine Room after bulkhead.
Bruce & Jim,
Beautiful sketch!. It certainly catches the essence of the wreckage in a way that is both technically accurate and ascetically pleasing,