How much does it cost to winterise a boat?

In the UK, budget £80 to £180 to winterise a small inboard diesel yourself, or £250 to £500 for a professional engine service and winter lay-up. For a typical 30 to 35ft sailing yacht, professional preparation of the engine, domestic water system and toilet costs roughly £350 to £750, with lifting, storage and covers charged separately.

Check what the quote includes

Ask for an itemised quotation. "Winterisation" can mean protecting the raw-water circuit against frost, or servicing the engine and draining every water system aboard. That difference explains much of the price spread.

For a yacht with a Volvo Penta MD2030 or similar small diesel, ask whether the price includes:

• Engine oil and oil filter replacement.
• Primary and engine-mounted fuel filters, where due.
• Raw-water cooling circuit frost protection.
• Checking the closed cooling circuit's antifreeze strength.
• Draining or protecting freshwater plumbing, calorifier, shower and toilet.
• Consumables, travel, waste disposal and VAT.

A winterisation-only quotation may exclude oil and filters. Change dirty engine oil before storage so soot and acidic contamination do not sit inside the engine all winter.

Typical engine costs

These figures are planning allowances. Engine access, location and the manufacturer's service schedule affect the bill.

• Small portable outboard: about £20 to £60 in DIY consumables, or £90 to £180 professionally for basic servicing and storage preparation.
• Small yacht diesel, roughly 15 to 40hp: £80 to £180 DIY, or £250 to £500 professionally with routine oil and filter work.
• Single larger inboard or sterndrive: approximately £350 to £750 professionally, depending on cooling layout and service scope.
• Twin-engine motorboat: allow roughly £700 to £1,500 for both engines; generators and domestic systems add to this.

For the small diesel, a typical shopping basket includes £30 to £60 of engine oil, £10 to £25 for an oil filter, £15 to £45 for fuel filters and £20 to £50 for suitable winterising fluid. Genuine Volvo Penta or Yanmar filters can cost more than recognised aftermarket equivalents.

Impellers, belts, anodes and gearbox or saildrive oil cost extra if replacement is due. Ask before authorising this work. A full annual service involves more work than basic frost protection.

Plumbing and other costs

Domestic plumbing is easy to overlook. Water can remain in pump housings, mixer taps, shower heads and calorifiers after the main tank has been emptied.