Most of the breakdowns we get called to in July could have been found in April. The yacht has sat all winter, some hoses have aged, the watermaker was never quite pickled, and the first long run to Formentera finds every weak spot at once.
This is the list we'd want a captain to work through before the season. It isn't a replacement for the manufacturers' service schedules. It's what we see go wrong most often, roughly in order of how much trouble it causes.
Raw-water cooling: start here
Every engine, generator and seawater-cooled air conditioning unit on board depends on seawater flow. It's the most common cause of summer breakdowns by a long way.
- Seacocks. Open and close every one. A seacock that has sat in one position all winter can seize, and one that won't close is a problem you want to find alongside, not when a hose splits.
- Strainers. Clean them all, check the lids seal, and replace cracked sight glasses.
- Impellers. If an impeller has done a season, or the engine has sat for months, change it. Rubber vanes take a set when they stand still. Keep the old one and count the vanes. A missing piece usually ends up in the heat exchanger.
- Hoses and clips. Squeeze the hoses. Soft, cracked or swollen ones get replaced. Double clips below the waterline should both be there and both be tight.
- Anodes. Check the engine and heat-exchanger anodes as well as the hull ones. Some are easy to miss.
Fuel
Diesel that has sat in a part-full tank over winter collects water from condensation, and water is what the diesel bug lives on.
- Drain the water separators and look at what comes out. Clear diesel is good. Water, black sludge or slime means the tank needs attention.
- Change the primary and secondary filters if they're due, or if you don't know when they were last done.
- If there's a vacuum gauge on the primary filter, write down the reading at idle and at cruising rpm. A rising reading over the season tells you a filter is loading up before the engine starts to suffer.
Main engines
- Check oil and coolant levels cold, and look under the engines for anything new. Fresh oil or coolant in the drip tray is worth tracing now.
- Start each engine and let it warm up alongside. Watch the exhaust: there should be a strong flow of water within seconds.
- Look at the alarm history on electronically managed engines. Faults logged last season are often still there.
- Check the belts for glazing and cracks, and that the tension is right.
- Run up to load on a sea trial and note temperatures and pressures at your normal cruising rpm. Those numbers are your baseline for the summer.
Generators
On most yachts the generator does more hours than the main engines, and it does them in the hottest part of the day at anchor.
- Treat its cooling side exactly as you would the main engines': strainer, impeller, heat exchanger, anodes.
- Look at the exhaust mixing elbow. Carbon and corrosion build up there, and a restricted elbow leads to high exhaust temperatures and shutdowns.
- Run it on a real load for at least half an hour, with the air conditioning and the watermaker on, not just lights and fridges. Plenty of faults only show up when it's working.
Air conditioning
- Clean the seawater strainers and check each AC seawater pump is moving water. You should see a steady flow from every AC overboard discharge.
- Change or wash the fan-coil and return-air filters.
- Pour some water into the condensate trays and make sure it drains away. A blocked drain becomes a damp ceiling panel in August.
- If the condensers or the chiller heat exchangers haven't been descaled in a couple of seasons, get it done now. Warm seawater shows up a scaled condenser very quickly.
Watermaker
- If it was pickled, flush it according to the manufacturer's procedure before making water.
- Change the pre-filters.
- Note the first salinity reading and the output. If either has moved a long way from last year, the membrane may need cleaning or replacing.
- Never start it in harbour water. Wait until you're in clean water offshore.
Hydraulics and stabilisers
- Check hydraulic oil levels and look for oil around the passerelle, crane, platform and stabiliser actuators.
- Run the passerelle, platform and crane through their full movement before the first guests need them.
- On stabilisers, run the system self-test if it has one and check the fins centre and lock.
Write it down
Keep a simple record of what you changed, what you found and the readings you took. It makes troubleshooting much faster in August, and it's the first thing we ask for when we're called out.
If you'd like us to do the pre-season checks, or there's something on this list you'd rather not tackle yourself, you can book a service online with photos, or call us on +34 971 251 374.