Keep on priming

Just another weekend of applying primer coat after primer coat after primer coat. You forget how much work painting is! Painting, anxiously waiting and checking for it to dry, then sanding, and going through the whole process again... and again.
As of now, I've got 4 good coats of primer on the aft section of the hull with only 3 so far on the fore and mid sections. I'm debating whether or not 3 coats of primer is enough. First off, I'm tired of applying the stuff. Second, 3 heavy coats seems like it might just be enough. Especially considering that I've got at least 2 gloss top coat that will be going on later. BUT since this is just lowly acrylic house paint, I do want to make sure I'm applying the necessary amount to hold up a good long time. Is three coats of primer and 2 coats of gloss top coat enough for a boat that will always be out of the water when not in use?