What it does is the GM solenoid just clicks and acts like it does not have enough voltage to turn the boat over...I have the 8 spade block for my wire terminals...Im sure I have another problem, wire to small etc, just want to fix it right with out rigging it....
Mike
Is the solenoid kicking the Bendix in then the starter motor stalling out? Sounds to me, as someone mentioned, either the starter needs rebuilt, or the battery is toast. Or both. Could be wiring issues, worth investigating, but start simple. The terminal block is not very likely the problem unless corroded badly.
Had a similar issue back in June. Brand new Marine Grade battery in March. Had issues with the alt belt in May, which required a few jump starts. I blamed the belt. Towed the boat 3.5 hours to Big River after a night on the charger (Which said it was OK on it's analyzer) Wouldn't start on its own from minute one. Even refused to start on a Jump in the end. Luckily, my truck runs two batteries, so i yanked one and had a good weekend. (Used Vice Grips for a terminal clamp, but worked OK)
Long story short, the beating I put that poor battery through destroyed it. Now run only Blue Optima Gel Cells.

devil
Don't assume a newer battery cannot be the problem. But I'm more apt to beleive the starter motor itself, in your case. It's a Chebbie!
Ray