Why Annual Maintenance Matters

A well-maintained boat is a safe boat. Saltwater, UV exposure, mechanical wear, and biological growth all work constantly against your vessel. Setting aside dedicated time each year — typically at haul-out — to inspect and service every system is not just good practice; it's essential for longevity and safety at sea.

This checklist covers the key areas to address annually, whether you're doing the work yourself or directing a boatyard.

Hull and Bottom

  • Inspect the hull for osmotic blisters, cracks, or delamination. Tap suspect areas with a mallet — a hollow sound indicates problems.
  • Sand and apply fresh antifouling paint to deter marine growth. Match the paint type to your sailing area (hard paint for racing, ablative for low-activity boats).
  • Inspect and grease the through-hulls and seacocks. Every through-hull should open and close freely. Stuck seacocks are a real emergency hazard.
  • Check the keel bolts for signs of rust staining, which can indicate weeping and potential failure.
  • Inspect the rudder for play, damage, and secure attachment.
  • Check and replace zincs (sacrificial anodes) if more than 50% depleted.

Rig and Sails

  • Inspect all standing rigging — shrouds, forestay, backstay — for broken strands, fishhooks, or cracked swage fittings. Run your hand along every wire carefully.
  • Check chainplates where rigging attaches to the hull for signs of corrosion or movement.
  • Lubricate turnbuckles and toggles with lanolin or a marine lubricant.
  • Inspect the mast and boom for corrosion, cracks at spreader bases, and loose fittings.
  • Check sheaves, blocks, and furling systems for wear and smooth operation.
  • Inspect sails for UV degradation along the leech, worn batten pockets, stitching failure, and chafe points.

Engine and Mechanical

  • Change the engine oil and filter. Most marine diesels call for this every 100–150 hours or annually, whichever comes first.
  • Replace the raw water impeller. Impellers can fail suddenly and cause overheating. Replace every year regardless of condition.
  • Check belts and hoses for cracking, glazing, or wear.
  • Inspect the stuffing box or shaft seal for dripping (a slow drip is normal; a stream is not).
  • Check the propeller for dings, barnacles, and proper pitch.
  • Service the fuel system: replace fuel filters, check for water in the fuel, and inspect fuel lines.

Electrical Systems

  • Inspect all wiring connections for corrosion and secure terminations.
  • Test all navigation lights and replace any failed bulbs or LEDs.
  • Test the bilge pump — both automatic float switch and manual override.
  • Check battery terminals and electrolyte levels (if not sealed); test battery capacity under load.
  • Test VHF radio — make a radio check and ensure DSC distress function is registered.

Safety Gear

  • Check expiry dates on flares and EPIRBs.
  • Inspect life jackets/PFDs for bladder integrity and auto-inflation cartridge condition.
  • Service or replace fire extinguishers as required.
  • Inspect the liferaft — most require professional service every 1–3 years.
  • Check jacklines, tethers, and harnesses for wear and secure attachment points.

Interior and Plumbing

  • Inspect hose clamps on all underwater plumbing — they corrode and fail silently.
  • Check the bilge for unusual water, oil residue, or debris.
  • Service the manual and electric bilge pumps.
  • Inspect LP gas fittings and hoses if your boat has a gas stove.

Keep a Log

Document everything you do. Note dates, parts replaced, hours on the engine, and any concerns for future attention. A maintenance log adds real value when selling the boat and helps you spot patterns before they become expensive failures. A small notebook in the nav station costs nothing and saves a great deal.