I'm currently restoring 2 polaris sl 750. I have taken care of all the engine issues, but on both jetskis i see a tiny hole to the right of the propeller. I had previously thought that it was where a hose could be hooked up but now i realize that might not be the case. Can i get any ideas on what i should do whether plug it up, let it be or get the thing for the hose. By the way right inside the hole is the battery on the inside, and i have intent on using it in brackish water if those too things make any differences... Thanks