Kenneth. comiserations old chap. Must have been terrible!
SOME of the foam chips are biodegradable, or made from cellulose of something and may not be much good. best to soak some first just in case. Other than that, anything would help.
We have discussed this before, and one method is to have something on the boat that floats but is held on with a water soluable glue.. this will melt after a while and the floater can pop to the surface tethered to the baot (which is the thing not to forget, a bit of line connecting the float and boat). A float could concievably be hidden in a Titanic funnel, for instance.
I would rather build in some expanded polystyrene , filling the sharp end or superstructure/whatever.
Ashley. Have a Titanic, not suffered so far,,,,,