Ask ten boat owners what an “annual service” includes and you will get ten different answers. Some think it is an oil change. Others expect the boat to come back as good as new. The truth sits in between: a proper annual service is a structured inspection and replacement of the parts that wear, so that small problems are caught before they leave you drifting outside the harbour.
This is the checklist we use on craft of all sizes along the Costa Cálida, the Mar Menor and the southern Costa Blanca. Your engine manufacturer’s schedule always comes first, but this gives you a clear picture of what a thorough service should cover.
Engine oil, filters and fluids
- Engine oil and oil filter changed with the grade your manufacturer specifies. Marine engines work hard at constant load, so running hours matter as much as the calendar.
- Fuel filters and water separators replaced. Diesel bug and water in the fuel are some of the most common causes of breakdowns we attend in summer.
- Gearbox or sterndrive leg oil changed and checked for water. Milky oil in a sterndrive is an early warning of a failing seal.
- Lower unit gear oil on outboards, with the drain plug magnet inspected for metal particles.
- Coolant checked or replaced on freshwater-cooled engines, at the strength and type the manufacturer specifies.
- Power steering and trim/tilt fluid levels checked and topped up.
Cooling system
Overheating is the number one engine complaint in the Mediterranean summer, so the cooling system gets particular attention.
- Raw water impeller replaced. Rubber impellers harden and lose vanes, and a single broken vane can block a heat exchanger.
- Raw water strainer cleaned and its seal checked.
- Heat exchanger, oil cooler and aftercooler inspected, and cleaned if the engine has been running warm.
- Exhaust elbow and mixing elbow inspected for corrosion or carbon build-up, a known weak point on petrol sterndrives.
- Thermostats tested or replaced on older engines.
Anodes and corrosion
Anodes are designed to corrode so that your drive, shafts and propellers don’t. We check every anode on the boat and replace any that are more than about half consumed. In the warm, salty water of the Mar Menor they can disappear faster than owners expect. We also look for white powdery corrosion on aluminium drives and outboard legs, which can point to a stray current or a bonding problem.
Fuel system
- Fuel lines, clamps and primer bulbs inspected for cracking and leaks.
- Tank vents checked: a blocked vent can starve the engine under load.
- Spark plugs replaced on petrol engines, at the interval the manufacturer gives.
- Injectors and fuel pumps noted for any sign of weeping on diesels.
Drive, propellers and steering
- Propellers removed, checked for dings and fishing line behind the hub, then refitted with fresh grease.
- Sterndrive bellows inspected: a split bellow can sink a boat at its mooring.
- Gimbal bearing and universal joints greased on sterndrives.
- Steering cables, hydraulic rams and helm pumps checked for play and leaks.
- Throttle and gear cables adjusted so that the engine engages cleanly.
Electrics and batteries
- Batteries load-tested, terminals cleaned and secured.
- Charging output from the alternator measured.
- Bilge pumps and float switches tested, both automatic and manual.
- Navigation lights checked, along with the horn, gauges and alarms.
- Shore power connection and battery charger inspected if fitted.
Hull, deck and safety
- Seacocks operated and their hoses double-clamped below the waterline.
- Hull checked for blisters, impact damage and the condition of the antifouling.
- Safety equipment checked against the date stamps: flares, extinguishers, lifejackets and the first aid kit.
- A sea trial at the end, under load, with temperatures and pressures logged.
How often?
For most leisure motorboats here, once a year or at the hours interval in your engine manual, whichever comes first. If your boat lives in the water all year in the Mar Menor or a busy marina like Torrevieja, a short mid-season check of the impeller, strainer and anodes is money well spent.
A good service ends with a written report: what was done, what was found and what to plan for next year.
Book your annual service
We service outboards, sterndrives and inboard diesels on craft of all sizes, at your berth, on the hard or at our base in Campoamor. See our boat servicing page, or book a service and we will send you a fixed quote before we start.
