Regular and consistent boat maintenance is the key to owning a boat that is safe and reliable, has a minimum of unexpected repair bills, looks good and retains its resale value. Whatever the vessel, it’s a continuous process requiring a constant eye on anything that may need attention, including engines, systems, fittings, chafe in ropes, sail damage and so on. That doesn’t mean that this aspect of maintenance has to be an onerous chore – it’s more an attitude of mind to look for the first sign of any problem and then monitor wear.

Yacht laid up ashore

Protect your investment and minimise expenditure by staying on top of your boat maintenance.

The old adage that ‘a stitch in time saves nine’ is just as applicable for today's yachts and motorboats as when the sailing ships carried the world’s trade around the oceans. This is especially true of mechanical and electrical systems and anything that may allow water to penetrate into the structure of the vessel, such as leaky deck fittings. Another key step is to keep the boat clean. As well as making it more pleasant for yourself and guests, this will help to keep damp and mould at bay – both inside and outside.

For most owners there are also season aspects to maintenance. The spring is traditionally fitting out season, where the whole boat is checked over and the bottom re antifouled to reduce growth of marine organisms during the summer. Read about how to prepare and apply antifouling paint here.

If done properly in the autumn, the laying up process will identify most of the tasks that need to be completed by the start of the following season. Although most boats are kept afloat, and often fully in commission, through the winter it’s still good practice to identify and list any potential problems at the end of the main boating season. If contractors such as marine engineers or sailmakers need to be engaged to fix any of these it’s much better to instruct them in October or November, rather than in April, when they are likely to already be at full stretch. See our laying-up and winterisation tips.

Yachts ashore in a busy boat yard

A planned maintenance schedule will produce better results than an ad-hoc approach.

Winter is often a popular time to tackle more major projects and upgrades – see best winter yacht maintenance projects and how to upgrade and improve your yacht. Equally, there are some tasks that are best done on a fine summer's day.

Engine maintenance

Diesel inboard engines need an annual service including changing oil, oil filter and fuel filters. Ideally this should be carried out before the winter lay up and the engine winterised at the same time. Daily checks include drive belt tension and condition, an examination of all wiring and pipe work to check for loose connections and chafe, and sump oil level and coolant level in the heat exchanger of fresh-water cooled units. Find out more about engine maintenance here.

Ignoring engine maintenance stores up problems for later.

Sacrificial anodes should be replaced when they are approximately one-third degraded. In practice, this often means annually. Examine the outer edges of the propeller blades for damage – surface pitting, accompanied a pinkish discolouration, is a sign of electrolytic action and should be investigated further. Also, check the cutless bearing in the P bracket for wear – it should be a snug fit around the shaft.

Damage to metal through-hull fittings is often caused by electrolysis – a white powder inside the hull around the fitting is a sign of dezincification and the fitting should be replaced. In any case, check all seacocks operate freely, and grease them before launching. Also, check log and depth-sounder transducers for damage. There's more essenatial information about through-hull fittings and seacocks here. Bilge pumps (and heads pumps) need periodic servicing. This may not be necessary annually if they are only used occasionally, but should be carried out every second year.

Fibreglass boat maintenance

A regular polish and wax will help to keep these looking like new and is especially important for deep colours, which tend to fade relatively quickly. Large areas on badly faded topsides are best done with an electric polisher.

Periodically check fibreglass mouldings for scratches, chips, stress cracks and other gel coat damage. Any cracks should be investigated to see how deep they penetrate, using a sharp chisel to open the crack into a v shape – if it does not extend beyond the gelcoat, a cosmetic repair of the gel is all that is required. However, if damage extends into the laminate below a professional repair will be needed. Also read about how to deal with fibreglass deck leaks.

boat maintenance: Yacht ashore awaiting re-application of antifouling

When doing regular tasks - like stripping, repainting and antifouling, you have an ideal opportunity to check for problems.

Looking after timber

Teak decks on fibreglass or metal boats have a limited lifespan and replacement is expensive – any signs of loose caulking, split planks or leaky deck fittings should be attended to immediately to prevent water getting under the deck. Much of the damage to such decks is the result of scrubbing with a stiff brush, which can wear up to 1mm per year from the timber. A soft brush, used gently across the grain when washing decks will avoid this wear, with the timber gradually acquiring a natural silvery appearance.

Wooden boats are at risk of damage caused by failure of the paint, varnish or epoxy coatings and the ravages of freshwater and frost. Salt water, on the other hand, is a mild preservative, so most problems are found where rainwater is allowed to settle, with any damage in the protective coatings enabling rot to take hold.

Lack of ventilation is the other key enemy of wooden structures. Dinghy covers should be made of a breathable material and yachts need a good flow of air through the accommodation areas and locker spaces, unless they are equipped with a marine specification dehumidifier. Indeed, this should be a priority on any boat, to prevent it becoming stale, damp and mouldy. The difference with a fibreglass vessel is simply that the structure won’t deteriorate, although soft furnishings and anything stored on board will certainly suffer if the interior is allowed to remain damp. For more details on this, read how to care for teak decks.

Safety kit

Looking after safety kit - and ensuring you have the appropriate gear on board - is an on-going part of boat maintenance. Flexible gas pipes have a five-year lifespan, but if they show any signs of perishing, or if braided outer cores are starting to fray, they should be replaced immediately by a qualified marine fitter. All safety gear should be given a full check and service each year (see 14 tips to make sure your safety gear is in order), with lifejackets examined more frequently for chafe or damaged stitching, and to confirm that the inflation bottle is firmly screwed in place.

Sails and rig

Examine sails for damage to stitching, as well as nicks, chafe and tears in the fabric – when sailing the smallest damage will show clearly against the sun. Pay attention to high load zones, batten pockets and the leech of headsails. There's more information on this in our piece on how to look after your sails.Checking the rig

Check the rig at least once a season.A full rig check is a sensible precaution at least once a year. A visual check won’t tell you everything – hairline flaws invisible to the naked eye can cause stainless steel to fail – but it’s a good place to start. Check all terminals and fittings for visual condition and security, paying particular attention to spreader roots and rigging attachment points. At the masthead check the halyard sheaves run smoothly and lubricate them sparingly. Also, check that spreader ends and other items that may damage sails are smooth and well protected with tape. Find out more by reading about basic rig checks and common problems.

Budgeting for maintenance

Many failures to maintain an older boat adequately stem from a lack of appreciation of the long-term costs involved. It’s fairly straightforward to budget for routine items such as racing sails that must be replaced frequently, but items with a longer lifespan are a different matter and it’s difficult to predict when they will reach the end of their serviceable life. It is, however, prudent to build a contingency fund from which to pay for essential replacements. I use rough estimates of the useful life of key components to budget ‘big ticket’ expenditure on my boats (see table below).

Maintenance tableIn many cases, items will last much longer than this, but others may fail prematurely. In any case, there’s no harm in being pessimistic about the costs – so for my 30ft cruising boat, putting £100-150 a month aside, in addition to annual maintenance costs, covers the bulk of any essential big ticket items in the long term.

For more maintenance advice read these features: how to paint a boat – our ultimate boat painting guide; cheap boat maintenance: 10 ways to save money; deck fittings: service and repair tips; marine electrics: the basics of 12-Volt systems plus 8 ways to make boat batteries last longer.

Written by: Rupert Holmes
Rupert Holmes has more than 70,000 miles of offshore cruising and racing experience, in waters ranging from the North Sea to the Southern Ocean and Cape Horn. He writes about all aspects of boat ownership and marine travel, including destinations, seamanship and maintenance, as well as undertaking regular new boat and gear tests. He currently sails around 5,000 miles per year and in the past couple of seasons has cruised from the UK to the Azores, as well as winning his class in the 2014 two-handed Round Britain and Ireland Race. He also owns two yachts, one based in the Mediterranean and the other in the UK.