Nothing better than a few cool wobbly pops and some nice clean tight sounds on the water...
Some of my best fish of the year were caught with the tunes cranked...
We put in a couple of amps, a sub and some nice speakers... it just hammers btw, no distortion.
I built a nice little sub box with the sub aimed at the floor about 3 inches off the floor in a 18.5 Double Eagle deep V cuddy cab...the only thing you can see is a slot running across the bottom of the box where the sound comes out onto the bridge. Designed it in such a way it goes right where the porta potty would go, built it out of 3/4 baltic birch ply and fiberglassed the box inside & out to protect against the elements. It's totally removable if need be, and completely out of the way, if fact if it wasn't pointed out you wouldn't even know it's there.
Also built a really cool amp rack to go inside the cuddy just inside the door on the vertical wall, ran 4 guage power wire with proper fusing and power distribution strips & blocks & fuse blocks, etc. It worked all year w/o any problems and we took it out for the winter as all of it was designed to be removed for the wet season/storage.
I would say some days if it was a bass happy song we wouldn't get a bite but other days it didn't seem to matter...so we would shut of the system if we weren't catching, and if we were all the better...keep it cranked.
We listen to all kinds of stuff, usually we would invite our guest to bring their favorite tunes... hard rock, classic (CCR works well

), techno, trance/ambient is awesome for later in the day on calm days for sunsets.
Overall it made this past summer's fishing even better...and I can't wait for next year.
Oh BTW if you put in some amps just make sure your boat has a nice dry cuddy and a charging system on the kicker...don't want dead batts
Remember, "When the Fish aren't Biting...the Fish aren't Biting!!"