There are a couple of things to consider when painting the inside of your boat. As the former marketing
manager for a specialty primer company here are a few things I know. Adhesion is a big issue otherwise you will have to do it again sooner than you like. Painting formica has the same adhesion issues. 1. Surface prep. You need to have a sound surface. Clean with acetone or MEK. Don't use anything that might leave a film residue. Old paint
is o'k if it is solidly adhered. You can put an oil
based primer over oil
alkyd paints but not latex. A latex primer will go over old oil or latex paint
Best solution for long term durability but not without some drawbacks is an oil based bonding primer. Sherwin Williams carries XIM 400W which is the gold standard for bonding primers. It sticks aggressively to just about everything including glass and formica. After a week you can only get if off with a grinder. Topcoats bond with it chemically. The downside is the stuff smells for a couple of days. You need to be out of the boat during that time. Just about any good oil alkyd topcoat will work as a durable finish. Oil alkyds are still available in quart containers which are exempt from VOC limits.
2.Go to HD and buy a paint primer combo paint. Prep surface well. Remember how you did it because you will be doing it again in a couple of years. The stuff will scratch off with your finger nail.
3. Use an epoxy
paint. A little pricey but works well.
latex paints and primers are flexible but will always be a little soft. It takes a week or so for the latex coatings to fully coalesce and attain their full physical properties. Personally I wouldn't use latex on the inside of a boat. A friend of mine did and he was peeling strips of it off in a year.