My boat a Hirricane GS 170 is docked and taking on water. I need to bigle out 3 to 4 gallons every 12 hours or so. I know the plug it not leaking and have tighted all mounting bolts for the outboard Mercury 90 HP. I have pulled boat and inspected hull and do not see any damage. Anyone have any suggestions of what else I could check where water may be entering boat?