from Home Depot is definitely a bad idea as almost all of the products they carry are architectural. These should never be used on a boat. "High Performance" or "Industrial" products can be bought at a good paint store that services industrial contractors for quite a bit less than Marine
labelled stuff. For example, Westmarine sells perfection two part polyurethane
at $129.99 per 1/2 gallon. I sell Benjamin Moore SuperSpec HP two part Aliphatic Urethane for about $105 Canadian per gallon. Thats well over twice the price
for a label that says "Marine". The only truly unique marine
paint is bottom paint
. Everything that would be used on the topside has a far cheaper equivalent industrial coating. Paint companies often have identical products with different labels and marketing
. Kitchen & Bath paints are the most common example of this. Topside paints are no different and it shouldn't be assumed that the word marine makes it better or worth the extra cost.