Question for the Free-Divers/Spearos

[ProfessorLongArms]

Looking into a kayak that's nice and light.
Anybody use a kayak for this kind of application they're particularly fond of?

I love my outback, but it's so much weight to haul down to the beach... Was hoping to shave off 10 or even as much as 20 pounds of hull weight.

Stability not as important as when I have 2-3 rods on deck and I'm sans wetsuit... for obvious reasons

This would be primarily surf launching.
Considering an old prowler or even a revo. Probably only for getting to the kelp, but possibly for covering a mile or two.

From a physics perspective, I'm trying to understand how much of a drawback there is to a lighter kayak, even if it's 13 feet (I see some prowlers @ almost half of my 90 pound hull weight outback)

I've only ever really paddled in a really long, heavy Trident with a rudder and an Outback.