Is a 13w7 enough?

If and you've read my other post about my subwoofer issues in my boat this season...you can tell I'm pretty fed up with dealing with tweaking my stereo. Last year I had an awesome sounding system with great bass and this year...same equipment new boat...sounds like garbage. I'm considering picking up a 13w7 off a friend but I wanted to hear what people thought about their output? Is a single sealed 13w7 with 1000w enough to keep up with well powered xs650'S and 4 rev 8's? I dont have the space to port it so I have to go sealed. The reason why I pick the w7 is the availability, sound quality and build quality from JL. But I want it to at least keep up without turning the rest way down!