Hi, I'm interested in buying a residential houseboat, and am looking for some advice. It's a 40' x 16' boat with an aluminum hull; one third of the hull has a leak along one of the seams, which the current owner is maintaining with the aid of a sump pump.

The pump comes on when there is 1/8" of an inch of water in the hull; it went off while I was there, and stayed off for the remaining 15 mins. He tried to repair it at one point with putty, but he didn't keep the putty in place (with a plywood support?) so the leak reappeared. Question - is this a big deal? Should I forget about it altogether, or should I at least pay for a professional to give me an opinion? The owner said that (if he was staying) he would get a concrete hull constructed and get the boat onto that; how much would that cost?

Alternatively, how much do you think diagnosing and fixing the leak in the seam would cost?I can cope with improvements/upgrades in the interior, but I am a newbie when it comes to boats, so the exterior I'll need to pay for the first few fixes.Thanks for any help.