looking good Are you using an air file? A straight sander used in body shops - I guess about 15 inches long.
I would not do a boat without an inline sander - that thing is worth its weight in gold... as long as you know how to use it properly!
Presume you're going back with gel on the hull bottom?
got some interprotect 2000 leftover from my uncles boat to coat all the bare glass with, then whole boats getting high build, 545 and topcoat