Since the weaknesses of plastic seem to increase with boat size, ie: weight and lack of structural rigidity, one might maximise plastic's strengths by sticking to shorter boats, with Looksha IV size probably being at the high end. Several plastic boat makers offer boats in the 14- to 16-foot range with hull shapes well suited to inshore work around waves and rocks. This is without even getting into surf-specific weapons.
Kayaks are very much creatures of their habitat. Deceptively simple, their diversity is actually vast.