We had a fuel tank leak, how do I get the smell out of our boat? What do you know about a aluminum tank leaking? We have a 1988 Bayliner 34' the tank is located under the back bed, she holds 200 gal, we don't know where the leak is on the tank. We have been told it will be costly to repair, I have agreed to turn her into a Condo on water for now until we can figure out what to do. I don't want to give up but I can not afford to go through this expense and not know where the leak is. Please can anyone help me restore my girl on water before they send her to a retirement home.

At long last, a response to your question. First, I know nothing about boats.. but I have a son in northern CA who does boat repair and gel-coat for a living. I know he is very good at his trade. I posed your question to him, and I will do my best to relate his answers: The fuel tank absolutely has to come out. You may have to cut out portions of the deck to remove it. If you are lucky the tank is not further held in with foam. He mentioned terms like bulkheads and stringers that are not in my lexicon. Removal of the tank could take 3 or 4 days. Do not have the tank repaired. Spend the extra $ to buy a new one, or have a new one built. Putting everything back together will take time. When I asked if this repair could cost $6000-$8000, he said easily. Bear in mind that he works in the CA Bay area where labor runs about $100/hr. He said to determine the market value of the boat to determine if such an expenditure is worthwile. If you have more questions, don't hesitate to ask, and I will ask him; he owes me. One reason why I never got into boats is that people say that a boat is a big hole in the water that you throw money into. Wishing you the best.

Boatless & Hurting! I don't have an answer, but I have similar problem. I have a 1996 Bayliner Avanti 3485 Cruiser which also has a fuel tank (150 gal) under the back bed. It is a diesel powered boat and first I just noticed a small of amount of diesel in the forward bilge mixed with some water. But it has gotten worse with time. I will try to remove the wooden cover (under the mattress and see if I can locate the leak). I think it is uneconomical to remove the top half of the boat to replace it, I will have to try to fix it if I can find it. If you have made any progress or found out anything new, I would like to know.

I know this may be a year too late, but I've dealt with this before... I spend a lot of time on the water and nine times out of ten, it isn't the tank that's leaking, it's the vent to the tank.

Since you both describe fuel in the bilge as well as a smell, take the inspection cover off that's above the fuel tank. You will see a panel on the tank itself with the fuel supply tube running to the engine compartment. If you're equipped with a fuel gauge, this is where you'll find the wire to the guage's float. Look for the largest tube into the tank. This is the fill tube, it'll run from where you put the gas in, to the tank. Usually, the vent is near where the fill tube enters the tank. If there are any rubber connections or gaskets, look them over thoroughly, if they're in good shape, look at where the vent thru-hull fitting is.

Hope this helped.

PS: If you try running around with a 1/2 tank of gas, and the fuel smell deminishes, there's a good chance the vent is the culprit.

Old Post, but a good question, Answers are a year apart, and another is due.
I would not jump to remove Tank, I would check all hoses in and out of tank, vent(s), and Fuel sender gasket was mentioned, May not be very expensive, may be a hose.
Fuel Vapors in the Bilge can blow up a Boat.

We also found out that our fuel leaked out of our gas tank these past two months (winter) 90, of 100gal were lost. Our boat was repaired for condensation from bad gas last year. That was a $3000 bill. What costs and repairs should we expect? We have heard that leakage is unsafe and expensive. We own a 2001 Doral SE, in mint condition with less than 300 original hours.

I found this page useful, I appreciated all the answers and I acted as suggested, checking hoses, conections, vents, since I wanted to avoid the most expensive part: removing and changing the aluminium tank. I have changed all the hoses including vents and the gas smeling continued. I had to remove the floor and get the tank inspected, there were three holes on spite that the tank appeared to be in good conditions. I had the opinion of two experts one of them told me: "if you are thinking on keeping the boat, change the tank because probably in few months you will have to remove it and repare it again. A new aluminium tank will last around 12 years and it is a matter of safety, an old tank does not provides any safety." The repair is not cheap, so by all means, when the tank leaks is because it is too old or because it was not properly built. Do not risk your life nor others life.

We have a 1998 Bayliner Trophy ~ with a leaking aluminum tank ~ the manufacturer of the gas tank is in Washington (Coastline equipment). They made and shipped us to the original specs (which they have) a new tank for $600 out the door. The boat repair shop here in San Jose, CA cut the deck, put in the new tank, installed a fuel filter, fixed the livewell connections, fixed the automatic bildge which had wires hanging all for $2,400. So for $3,000 we can take the boat out on Monterey Bay and not worry anymore ~~ worrying SUCKS!