Lots of options. Hard to say for sure but I would probably try to fill inject some thickened epoxy
in the holes trying to get a blob under the deck. Then put in the screws and allow to harden. Use microfibers to thicken the epoxy
. You might need to open the holes a bit and use a wire to remove some of the foam under to create a cavity for the epoxy
. You probably wouldn't be able to ever remove it again however. Cleats
should have backing plates but hard to say whether a 17 foot power boat was built with them.