Say you want to drive the moisture out of gelcoat. I've used a heat
gun to do it and was surprised at how much water came out.
So, what would a high power microwave unit do? Water absorbs the
microwaves much better than the polyester so it would get hot and come
out. This would avoid the months of waiting for a hull to dry if you
are repairing blisters (a real scam as blisters are not a real
problem).