Balsa cored hulls - old boats
Spent over $900.00 doing three surveys (#2 & #3 were partials) on three boats with cored hulls and all the boats were mid to late eighties. Every one of these boats was in beautiful condition with loving owners but all three were basket cases below the waterline. Gave up on cored hulls and bought a solid glass hull. Never had a flex problem or any signs of it. Just my .02 cents...