I was poking about in the port side front deck locker and I realised that under the locker floor must be a void. This must be about 30" long and is in front of the heads bulkhead. I have not tried to estimate the buoyancy in there but of course it may be full of water! Has anyone delved into one of these and was it watertight, filled with foam etc. On reflection this locker cannot go right down to the bottom as it could not then drain.
I might get a fibre optic inspection probe, drill a little re-sealable hole and have a look out of interest, if I do I will report back.