not real sure what your transom looks like, maybe you could post a pic?? there are several boats at my marina with speakers mounted in the transom and most of them look really good. you don't mention if you're replacing your head unit or what kind it is but Fusion and Kenwood both make a unit that has seperate zone volume controls. each of them can be worked via a wired remote (or two if you choose) so that would give you the ability to isolate your rear speakers if/when you prefer to do so and depending on where you mounted the remote(s), you wouldn't even have to get out of the water. as far as actually mounting speakers, i'm not familiar enough with your boat to give any advice on that. is there something in particular that is worrying you about doing it other than cutting a 6" hole in your nice shiny fiberglass? just be sure to check clearances and access for speaker fit and wiring.