Guide · Season
Boat winterization and spring commissioning checklist
Winterizing protects the engine, the fuel and the cooling system from standing still and from frost; spring commissioning reverses it and checks what aged over winter. Steps marked with a source in brackets come from Volvo Penta's operator's manual, Yamaha's storage guidance or the BoatUS spring checklist; the unmarked ones are general good practice. Your engine manual has the model-specific details.
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Winterization checklist
Engine and fuel
- Engine oil and filter changed before the layup, so the engine stands with fresh oil
- Fuel stabilizer added and run through the whole system before shutting down (Yamaha)
- Tank filled: Volvo Penta says completely full, Yamaha says 7/8 full, to limit condensation
- Outboard fogged (Yamaha: "Fog your engine")
- Seawater system cleaned and inhibited (Volvo Penta)
- Impeller removed from the seawater pump and stored in a sealed plastic bag (Volvo Penta)
- Engine coolant drained or checked for frost protection if the engine may be exposed to freezing (Volvo Penta)
Electrics
- Battery leads disconnected, batteries cleaned and charged (Volvo Penta)
- Batteries charged fully before storage and the charge checked monthly (Yamaha)
Boat and gear
- Water tanks, pipes and pumps drained
- Hull, cockpit and bilge cleaned and dry
- Cushions, sails and electronics taken off or stored dry
- Cover fitted with ventilation
- Safety gear checked: what expires before the next season goes on the shopping list
Spring commissioning checklist
- Impeller installed in the seawater pump, replaced if the old one looks worn (Volvo Penta)
- Rubber hoses checked and hose clamps tightened (Volvo Penta); clamps with rust replaced (BoatUS)
- Drive anode replaced if less than 50% is left (Volvo Penta); anodes more than half wasted replaced (BoatUS)
- Outdrive bellows inspected for cracked, dried or deteriorated spots (BoatUS)
- Stern drain plug installed (BoatUS)
- Batteries connected and charged
- Belts, steering and throttle checked
- Bilge pump and float switch tested
- Navigation lights, horn and VHF tested
- Flares, extinguishers and lifejackets checked against their dates
- Engine run on the water and checked for cooling water flow and leaks
Both lists as a reminder
Seaworthy has a "season start" interval: tasks on it come back every spring with the lead days you choose. Set the layup tasks with a fixed autumn date and the commissioning tasks for season start, and both lists arrive on time every year.
Common questions
Should the fuel tank be full or empty over winter?
Full, with stabilizer. Volvo Penta says to fill the tank completely to avoid condensation; Yamaha recommends storing with the tank 7/8 full and running stabilizer through the whole system before shutting down.
Should the impeller stay in the pump over winter?
Volvo Penta's laying-up instructions say to remove the impeller from the seawater pump and store it in a sealed plastic bag, then refit it in spring and replace it if it looks worn.
What do I check when the boat goes back in the water?
Impeller, hoses and clamps, anodes, outdrive bellows, the drain plug, batteries, bilge pump, lights and the dates on the safety gear. The list on this page is printable.