I have a 1977 Formula 233 with the usual rot in the transom and stringers. The worst part of the demolition necessary toward the restoration effort includes removing the worthless, saturated foam floatation. After I cut the floor out, there was still the 1-2" of flooring left around the perimeter with foam underneath extending under the floor edge about 6" to the chine. What tool do use....? A string trimmer works wonders in removing the foam in all the weird places but you will use alot of string.