hey, thank you for this advice !
actually the hole is accessible from one side only since the other
side is inisde the waverunner.
can theese instructions still be applied to 1 sided fix ?
maybe with some small modifications ?


Looks like you are not gonna get a lot of help here... Maybe you
should not have said it was a waverunner ... But anyway, it should
be an easy fix, however might need more info to send you on the right
path. Do you have access to both sides of the part? If so there is a
nice keyway patch technique that Payson and others use where you sand
the edges on both sides to form a bevel on both sides. Then you put
some cloth or mat with resin into the hole and cover both sides with
waxpaper and something to hold it in place until it dries, painting it
after is out of my range..
If you need more info of need to ask more questions, give me a buzz,
my number is on the front of my website, I take calls days, weekends
too. Please not to early or late...
Scotty from SmallBoats.com