I just did that yesterday on my G3 boat. The front deck on mine underneath the carpet is 3/4 inch treated plywood so it made it somewhat easier. I had to cut a small piece of carpet out and then cut a 2 and 3/4 diameter hole for the center of the base to fit down in...The put in six big screws. If the deck on your boat has a aluminum floor you will have to take a hole saw to cut the 2 and 3/4 hole then if you can get underneath it somehow and use bolts and nuts and washers to fasten your base down. If you cannot get to the underneath side I guess you could drill 6 holes big enough to get toggle bolts or moly's through there that will fold out against the metal and give you support.