What's Good? Looking for some advice about speakers?

I've got a Sea Doo Sportster, I just am learning how to wakeboard, and want some speakers on the boat, since it makes the whole experience way less frustrating with some music haha, anyway..

I'm looking for some nice speakers, they don't have to be top of the line hear them across the lake, but it would be nice to hear the speakers from 50ft back lets say?

What would you guys recommend, and also what all do you need?

Speakers An Amp? A sub?

Also how do the speakers get hooked into the cd player? All questions I'm trying to figure out, so any help or advice would be awesome, thanks guys!