I agree with all that's been said. As regards a heat gun (recommend Bosch) and lots of sanding. For this I'd get a good quality orbital sander. This is something that you'll use many times over the years and I'd get a good one (Makita; Bosch, etc - as they say you get what you pay for). Getting epoxy
off a cabin sole
can be a bear of a job and the only way to do it is with a heat gun and flat scraper. Once you get in the right plane sometimes you can elevate large portions of epoxy/old varnish using a flat spatula and heat gun.
The wood in your boat seems very stained and may not be salvageable (you could try bleach here). What you may consider, if this is the case, is to use the old cabin
sole as a template, get some good quality marine plywood
(3/4") and make a new cabin
sole. In most sailboats the cabin sole is beveled and I would use a saber or reciprocating saw (rent one or buy one). Then I would order some teak and holly laminate; Maine
(York - Maine Coast Lumber
, 35 Birch Hill Rd, 03909 800/899 1664) and epoxy this to the marine
ply (West System 105/205). And then give it a good sanding and then about 8 coats of two-pack Epiphanes sanding between each coats using 400 grit sandpaper between the last few coats. A power orbital sander on a nice flat surface makes this an easy job.
I did this to create a cabin sole in my anchor locker
on my Hinckley 50 yawl. After a few coats of Epiphanes Two-pack and gloss, I swear that it looked better than the teak and holly cabin sole in the focs'l and main cabin (some of the guys at Hinckley agreed).
Good luck and have fun.