Boat maintenance

It is important to ensure your vessel is in good order by inspecting the key features of the vessel each time before you leave home or the ramp, mooring or wharf. The major causes of breakdown at sea are engine failure, fuel shortage or contamination, mechanical failure and battery failure.

The vessel checklist

  • On entering the vessel, and before operating any switches or engines, check for petrol and/or LPG odours; fix any faults before you go out
  • Ensure the vessel is well ventilated to prevent carbon monoxide build up from exhaust systems
  • Inspect the bilges. If there is more bilge water than usual, find and rectify the fault. Note: when pumping bilges be aware of the environment. Polluting the waterways is an offence
  • Check fuel, engine oil and coolant levels. Fuel should be fresh and not last year’s. You should have enough fuel for the full trip plus reserve. Examine batteries, terminals etc. Do the same for the second engine if carried.
  • Check the fire extinguisher is in good condition
  • Ensure there is sufficient fresh water and food for the length of the voyage with some extra in case of emergency
  • Make sure your navigation lights are in working order
  • Self-draining holes should be clear
  • Ropes and lines should be in good condition and stored ready for use
  • Steering cables and connections must be in good working order
  • If your vessel is fitted with a kill switch, make sure you have the correct lanyard
  • Inspect the battery
  • Check that appropriate anchors are on board and are properly rigged, stowed and ready for use
  • Have one appropriate and accessible lifejacket for each person on board
  • Children should have suitably-sized lifejackets and look at means of rigging lifelines in open areas so that children have enough handholds
  • If you have a radio, make sure it is on and working. The best way to do this is to report the details for your vessel and voyage to a coast radio station or local base station
  • Have up-to-date charts showing the area of your intended trip, especially any harbours, ports and other potential refuges from rough weather
  • Ensure you have a complete first aid kit
  • Essential tools and spare parts should be in good condition
  • Keep a sharp knife in a handy place; you may need it to cut ropes etc
  • Have a rescue quoit or lifebuoy ready for use
  • Have a whistle, mirror, marker dye, flares for emergency signalling
  • Do not overload your vessel
  • Don’t forget the bung!

Recommended spare parts (miniumum suggested items)

Spare part Outboard powered vessels Inboard powered vessels Yacht
Pulley belts Yes Yes
'D' shackles Yes Yes Yes
Fuses for motor and radio Yes Yes Yes
Propeller Yes
Spark plugs Yes Yes
Starter cord Yes
Fuel filter Yes Yes Yes
Shear pins for propeller / spare nuts and bolts Yes Yes Yes
Roll of waterproof electrical tape Yes Yes Yes
Spare fuel line Yes Yes
Electrical wire Yes Yes

Recommended tool kit (minimum suggested items)

Tool Outboard powered vessels Inboard powered vessels Yacht
Bolt/wire cutters Yes
Adjustable spanners Yes Yes Yes
Small metal file Yes Yes Yes
Screwdrivers Yes Yes Yes
Hacksaw and blade Yes Yes Yes
Pliers Yes Yes Yes
Wire brush Yes Yes Yes
Water displacement spray Yes Yes Yes
Spark plug spanner Yes Yes

Motor maintenance

Regular maintenance will help to ensure some of the following parts won’t let you down.

  • Water pump: Replace regularly especially if you have been operating in the shallows and stirring sand or mud. Water pump impellors also deteriorate if not used for lengthy periods.
  • Fuel filters and lines: Filters become clogged and lines can harden with age and exposure.
  • Propellers: The bushing of the propeller can fail especially if it has hit sand or rocks. Always carry a spare shear pin.
  • Spark plugs: Plugs can break down unexpectedly. Carry spares.
  • Gear box oil: Snagged fishing line on the drive shaft is a common cause of leaking gear box seals. Water in the gear box will eventually cause it to fail. Regular oil changes will prevent this.

Some of the causes for engine failure are minor, so you should be able to troubleshoot a problem. Take time to learn how to:

  • Change the filter and primer bowl
  • Clean and change spark plugs
  • Check for spark
  • Check and replace fuses
  • Change the propeller
  • Clean battery terminals.

Don’t be a backyard mechanic, have all major servicing done by a qualified mechanic.


In the interests of promoting the use of cleaner, greener, locally made fuels in NSW, the State Government has taken steps to ensure the broader use of biofuels.

Biofuels are suitable for most applications where they are cycled quickly. Although marine engine manufacturers are producing new engines capable of using biofuels, boat owners need to be aware there are still significant safety and fuel management issues.

Implications for petrol engine owners

Normally ethanol blended fuel is not recommended in a marine application because ethanol absorbs water readily and it may separate from the petrol, resulting in engine failure.

Ethanol is a solvent and may cause problems for carburettors, fibreglass fuel tanks, rubber fuel lines, fittings, seals and filtration systems, particularly in older engines and non-standard engines.

To avoid petrol with ethanol, buy either higher octane rated fuel which doesn’t contain ethanol or regular unleaded petrol from a marina.

Implications for diesel engine owners

Biodiesel exhibits poor oxidation stability and is a medium for microbial growth. Both of these factors contribute to its breakdown, which can result in accelerated engine wear, the breakdown of engine lubricants and blockages of oil and fuel filters. Its solvent properties can result in damage to certain components including seals and hoses.

Diesel blends of up to five per cent biodiesel do not require labelling, so always ask your marina operator before you fill your tank.

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