I think this was the "new improved" version of MPX that was released 2-3 years ago.
I used this and Interspeed (in its various guises) over the 14 years that I owned my last boat "Aries II" (non-RIB, I'm afraid).
Tue - You certainly wouldn't get away with just "green slime" if you moored your boat on the Hamble! Even Interspeed Ultra (2 coats of the stuff) couldn't really cope with the nasty crustations that live on that river.
Having said this, I did used to paint the "boot top" (apologies if this is a "yachtie" expression - I am not a "raggie") with Trilux but I frequently cleaned it with a nylon scratchy pad, so I had probably rubbed most of the paint off before the end of the season.
I don't really think that Trilux was that great for the sterndrive either, as the paint had a job to stay "stuck" for very long. But there's not a great deal to choose from these days.
If you decide to use Interspeed, do make sure that you leave a gap (I think 1" is recommended by those who are supposed to know) around the o/b bracket or other such mounting, as Ultra will attack the aluminium. Well worth keeping a close watch on the anodes too!
I did strip the paint right back to the gelcoat once but I really can't remember if I primed the hull before antifouling. I did epoxy it though (6 coats - preventative reasons), so I might have used this as the base. Sorry - Not much help, I guess!