I can summarise the International debate for you!
It was claimed international Toplac and Japlac were the same product, with Toplac being the expensive marine option- they are not the same-FACT!
I however did use Japlac on my boat, 2 coats of primer and 2 coats of gloss, using a 6" sponge roller, and over a year later it still looks as good as when it was done, good deep shine and good abrasion resistance.
BUT, my boat does not stay in the water, it goes in for two or three days at a time, every 5 weeks or so between March and September and spends the rest of the year indoors in the garage.
Also, if you do use Japlac, keep the boat indoors and heated for 24 hours to ensure full drying and a hard shell finish, otherwise it takes a good long while to fully cure!
It's half the price of Toplac, but probably half the quality as well. Done properly like above it seems to last fine, but time will tell I suppose!