Don’t forget your pre-season checks

Sea Start, the marine breakdown assistance specialists, share their top tips on pre-start checks

“The spring is always a busy time for Sea Start with boat owners using their boats for the first time after the winter and new people with their new boat. Each year we carry out nearly 2000 breakdowns to all sorts of boats of all shapes and sizes. Electrical faults incorporating batteries, alternators and management systems”, explains Nick Eales from Sea Start.

At the beginning of the season your pre-start checks are more important than ever. Here are some of Sea Starts top tips to help keep you boating throughout the season.

Images for preseason checks from Sea Start

Engine Checks

1. Check fuel level and ensure the fuel valve is open (remember fuel gauges in boats are very unreliable unlike our cars).

2. Engine and gearbox oil levels (check your manual for procedure for gearbox oil level).

3. Check your sea cock is open.

4. Have a good look around the engine to check any potential problems

  • Electrical wires chaffing
  • Rusty or loose jubilee clips
  • Any tools or rags left by mistake
  • Check for any leaks

5. Check the belt tension (if it has been replaced over the winter then check it again after the first run out as it may bed itself in and loosen).

Images for preseason checks from Sea Start

6. Check the fresh water level in the header tank if fitted. This should be between the minimum and maximum level - don’t be tempted to fill to the top.

7. An engine bilge should be as clean as possible making it easy to notice if we develop a leak or if anything like a nut and bolt fall off before it gets more serious.

8. Check the battery switch is on and the throttle is not in gear.

Powerboats are likely to have more fluid levels to check, such as power steering fluid and stern drive reservoirs.  These have specialised oils in them and worthwhile carry spare onboard.

With two stroke outboards - don’t forget to fill the oil reservoir and always carry a spare.

One of the common breakdowns at the beginning of the season is overheating so here are just a few things that may cause it and things to look out for.


1. Never assume the sea cock is open especially if other people have been working on the boat.

2. On the initial start-up especially when the boat has been put in the water for the first time and the system is dry, it is a good idea to increase the revs of the engine in order to draw the water through the system.

3. If the salt water pump is worn then you may need to prime the system through the strainer. To do this shut the sea cock, open the strainer and fill the pipe that goes to the salt water pump. I suggest no more than half a kettle full, don’t keep pouring water in because it will eventually find its way in to the cylinder head.  Replace the strainer lid, start the engine, open the sea cock and increase the engine revs and check the exhaust for water coming through. Check five minutes later before you leave the dock just to check it’s still coming through.

4. A way to check how worn the salt water pump is to look at the face plate.  If it’s badly worn like this one it will be obvious, in an emergency the plate can be reversed.

5. The other common cause of overheating is air being dragged in through the strainer which normally occurs after the strainer has been checked. So, if you take the lid off be meticulous about putting it back on ensuring the seal is in place. A little Vaseline or grease helps to make a good seal.

Images for preseason checks from Sea Start

What are the secrets to reliability? 

  • Keep the fuel tank as full as possible
  • Regular all-round visual checks of engine noting any deterioration
  • Service as per the manufacturer’s instructions, oil changes help prolong the life of the engine
  • Inspect you pre-filter more regularly, i.e. before big trips, or after motoring in rough weather.
  • Check the seal around the deck fuel filler cap, to prevent water ingress into the fuel tank
  • Always oversea the fuelling and watering of the boat, people do make mistakes!
  • Check the drive belts for tension and wear and tighten when necessary
  • Diesel users use a fuel additive to prevent diesel bug
  • If your batteries aren’t sealed, check the water levels in them top so the plates are covered with distilled water
  • If you run the engine whilst alongside for any period of time to charge the batteries put in gear if you are tied up securely to prevent glazing of the cylinder bores. 
  • Accelerate gently
  • Don’t run the engine at full power for long periods
  • Use the boat as much as possible!!

This is also a good time to check that your anchor is secure to the boat and you have sufficient rope and chain for anchor to be effective. A good anchor is vital on any boat, in times of difficulties it can stabilise the situation so help can arrive.

Sea Start is now in its 30th year offering a fast-response marine breakdown service to sailors and motor boat owners on the south coast of England and shoreside attendance on the north coast of France and the Channel Islands.  To find out more about Sea Start visit