I am having trouble finding a leak in the bilge. I pump water out before we leave port and as we motor/sail keep an eye on it and we get little if no water in bilge as we are out. After docking we will get 2 or 3 inches in bilge in 10 min. or so. We again pump and have small amount coming in for an hour or so then it seems to quit. Any thoughts? Keel bolts? Can the bolts be tighten with boat in water? Thanks in advance.Jim and Becky