The word Suck doesn't even come close, and Well Yes the tape was still holding strong, I had to cut it all with a razor blade...But Damn... Why put an adjustable Amp, where you cannot reach to make any adjustments....I don't get it??And to NOT even Amp up the SUB..!!!!!Holy Crap, there's so much to make right on this boat, Don't get me wrong...It's great and it's the nicest boats I've ever seen, but it's going to be a task just making things operate right, like now each speaker is it's own channel....Yeah....
I am concerned with a couple things here. First is you state you cannot get to the adjustments. If you have changed the wire configuration you no doubt need to change adjustments. The amp is multi channel, has x-overs built in, x-over adjustments, switching for mode (2,3,4 channel), gain controls. Second you state the Sub not amped . . . what does that mean. Most of the Sea Ray factory installs have one sub connected bridged to two channels of factory installed amp. You never mentioned your sub did not work but you did mention adding a second sub.
I was on two Sea Rays this week at Lake Ozarks. On both intsalls I was able to see amps yet needed a mirror to see the switching and adjustments. As long as you can sneak your hand and a screw driver bit you can make all the adjustments.
BTW . . . one system was factory\original and the other was "professionally" installed. A few minutes of sorting and a few minutes of adjustments we were able to do a major tune up that included maximizing all full range speakers first and then dialing in sub(s).
Here is detail on what I do: http://clubsearay.com/showthread.php/40568-Maximizing-Your-Multi-Amp-amp-Sub-Sound-System