Guide 01 stop, check, call
I smell gasoline, or see fuel in the bilge
Fuel vapour can explode. What to do first, what to look at, and why this one goes to a technician.
Stop first
- Do not start the engine. The Coast Guard: "Do not start the engine until all traces of fuel vapors are eliminated."
- Put out anything that burns (cigarettes, stove) and get people off the boat or well away from it.
- Open ports, hatches and doors to let the vapour out.
- Do not pump fuel or oily bilge water overboard: discharging oil that leaves a film or sheen is prohibited, and a discharge must be reported to the National Response Center, (800) 424-8802.
Checks an owner can do
- Once the smell has cleared, look (without tools) for wet or stained hoses and fittings around the fill, vent and tank, and photograph what you see for the technician.
- If you have just fuelled, run the blower for at least four minutes and do the sniff test before starting, as the Coast Guard describes for every fueling.
- Note when the smell appears (after fueling, underway, at rest) and write it in your log.
Call a certified marine technician when
- There is liquid fuel in the bilge, or the smell comes back.
- Any hose, fitting, tank, pump or filter in the fuel system needs replacing or tightening.
- The blower does not run or its hose is torn or blocked.
Sources
- Boater's Guide: Fueling Precautions (PDF page 43), U.S. Coast Guard Boating Safety Division
- Boater's Guide: Ventilation, including the blower warning label (PDF pages 22-24), U.S. Coast Guard Boating Safety Division
- Boater's Guide: Pollution Regulations, oil discharge (PDF page 26), U.S. Coast Guard Boating Safety Division
- 33 CFR 183.610, Powered ventilation system, Code of Federal Regulations (via Cornell LII)
Reviewed 2026-10-08. Your manufacturer's instructions come first wherever they differ from this page.
Keep a record and brief your technician
Log this problem on your boat with the checks above as a checklist. Tick what you have done, then print a one-page technician brief: the boat, engine hours, what happens, what you already checked and the boat's recent work. When it is fixed, it goes into your maintenance log.
The technician brief is part of Skipper: $1.95 a month or $19.50 a year. Free during preview. Pricing