Yes, polarity matters. Also, speaker wire in itself, doesnt have a positive and negative, its just 2 wires that are identical. They only have polarity when hooked up. For this reason, there might be 2 different colors used if its basic primary wire, or if its traditional 2 conductor speaker wire, one of the conductors will have a tracer of some kind. This allows the installer to keep track of what he hooked to the POS and NEG at one end, when he gets to the other end. On the Wet Sounds Rev-410, the red wire is the POS and the black is the NEG.
Did the boat come from the factory with the amp and pair of 410's installed?