"All foam soaks up water, all of it".
ummmmm I totally disagree with that statement.
anyone that has spent any time around boat docks,
marinas and boat yards know that a lot of floating docks
are made with foam blocks. Yes, absoutely, there are "some"
types of open cell of foam that soak up water like a sponge.
On the other hand, there are types of closed cell foam that are
totally impervious to water intrusion.
The word "styrofoam" incorrectly refers to expanded (not extruded) polystyrene foam,
commonly called
EPS Foam or
Closed Cell Foam such as disposable coffee cups,
coolers, or cushioning material in packaging, which is typically white and is made of
expanded polystyrene beads.
EPS Foam is the correct term for any form of the Expanded PolyStyrene products.
Expanded PolyStyrene Insulation is a lightweight, rigid,
closed cell insulation.
EPS is available in several compressive strengths to withstand load and back-fill forces.
not to undermine your experience with waterlogged foam, (I have experienced it also)
but, a quick Google Search of "Styrofoam vs EPS foam" can provide enough accurate information
for one to make his/her own judgement of what foam to use for any particular application. In our case, boat flotation.
jus my Dos Centavos
.