if you are l;ooking for good spkrs on a budget
both best buy and circuit city sell indoor outdoor black yamaha spkrs that are second to none apx $100/pr
they are efficient enough to run without amp or us an amp and they are brilliant
or spend $400 on so bazooka cans and you need an amp
i was at a wakeboard fest earlier this year check out "wet sounds" if you want the best and no budget
Some 6 inch PVC with a pipe cap on one end and a flange marine texed into the other end and you have the same thing for less than 100 bucks with speakers.