To answer a few questions here are the other two lights I used to do the accent lighting on the boat.
I used the round light to replace the courtesy lights in the back and I also add two toward the front of the bow as courtesy lights up front.
I used the black ones to shine down above the speakers and cup holders in the back. I wired them all into the courtesy light switch. They were super easy to install. On the interior I removed the courtesy lights in the back and just fit the round ones over the old hole. The power cord comes straight out of the middle of the back, and it already has 3m sticky adhesive attached. On the front ones I just used a counter sink bit to make the dimple in the fiberglass, maybe and 1/8 in diameter, then I took a regular drill bit that was just smaller than the dimple and drilled a tiny little hole. the cord is very thin and will fit in a tiny hole. The lights above the speakers I just fished the wire up behind the side cushions and used 2 sided tape to adhere to the back of the cushion. Very easy, no drilling. PM me if you have any specific questions