Expanded polystyrene question

I have an old Hobie Mono Cat sailboat, which has an ABS hull filled with expanded polystyrene flotation foam. The foam has trapped/absorbed water and the hull weighs at least twice what it should.

Is there any way to dry out the foam? The two hulls do have voids in them.


Thanks.

 

I have seen cases where a foam-filled boat, left with hatches and drains open in the sun for several weeks to several months, dries out to the point where it's more or less back to normal. But the mould and the cell damage in the foam will remain (if it's wet, it IS mouldy) and you'll get the exact same problem in a couple of seasons. The only 100% sure fix is to dig out the damaged foam and replace it.