Thanks for your inquiry. If your boat was built prior to August 1, 2013 you will have a fuel vent in your hull side. If the tank is overfilled, fuel will run through this vent and into the water. There is no way for raw fuel to get into the boat if the vent system is intact and there are no leaks in the tank. For safety’s sake, please check your bilges to see if there is any raw fuel in any of the bilge compartments. If there is then you will need to find the source of a leak. Fumes are another story, and can be volatile. Airing the bilges out by running a blower or leaving hatches open can sometimes solve a problem with gasoline fumes. The ultimate test is to have a qualified technician pressure test the fuel system. Please call me if you have any questions about how to solve thie problem described. Regards, Joe Brenna, V.P. Customer Service; Intrepid Powerboats (727) 548-1260 ext. 229