boat maintenance tips

boat maintenance tips

from river canal rescue

In a bid to reduce the number of incidents on our waterways, River Canal Rescue (RCR) shares the main causes of this year’s call-outs and offers some maintenance, grounding and lock cill tips to help boaters enjoy stress-free cruising in 2020.

During 2019, RCR on average attended 105 call-outs a week (covered by its membership service). Of these, 18 per week were for major rescues and repairs, chargeable outside membership, the remainder were classed as minor.

Minor is defined as situations which on attendance, can be resolved (within two to three hours) without the need for a full rescue team. Major, as submerged, partially sunken or grounded craft, plus salvage work (engineers typically spend a day on each call-out).

Minor call-outs were primarily due to fuel, alternator, electrical, battery, cable, cooling system, gear box, starter and propeller problems. They included;

Gearbox, propeller, drive plate, coupling, prop shaft, engine mount, hull and rudder damage, due to hitting underwater objects or locks

  • Loss of propellers and nuts/rudders coming away
  • Domestic water ingress due to a lack of bilge pumps
  • Engine electrics catching fire

maintenance tips

RCR managing director, Stephanie Horton, comments: “Fuel problems are mainly caused by diesel bug and contaminated water. Diesel bug is an enzyme that lives off water in the diesel, either appearing as black dust/ soot or a black slime/jelly. Once in the system it clogs the engine’s fuel arteries and stops the engine working. Mild cases will respond to a fluid ‘Marine 16’; it prevents bacterial growth and kills anything that may be forming in the tank. More severe cases require a diesel bug shock treatment. Dirt and debris can also block filters and contaminate fuel so check and service regularly.

“Alternators operate in a damp, hot environment which is not good for electrics. If the bilges are full of oil and water when the engine’s running, it will be thrown over the engine, hitting the electrical components. If left for a long period of time, rust can also develop and affect their operation, so it’s important to check the bilges and run the engine frequently.

“Electrical issues are usually due to overlooked connections. Check for corrosion, wires coming away, loose connections or disconnected wires before starting a journey and use a water resistant spray or petroleum jelly to stop damp getting into isolators and block connectors.

“Starter systems must have the right batteries. A cranking battery delivers a high output quickly while a leisure battery delivers a lower continuous output, so needs regular charging to maintain capacity. If in a good condition, each battery in a bank generally requires two to three hours charging as a minimum to keep them topped up and will require more if discharged.

“Each battery cell can affect the whole battery bank so to prevent deterioration, regularly check and top up the cells’ water levels with de-ionised water. If one cell’s water level drops to below 50% it will bring the battery bank capacity down to the same level, irrespective of how good the other batteries are. Never mix batteries and always replace a whole bank of old with new.

“As most of the cable terminus is set outside, if not used regularly, cables will rust. To prevent this, grease the end of the cable, particularly if leaving the boat for a long period of time, and when setting off, check for any roughness or stiffness. If fitting new cables, keep bends to a minimum (they’ll suffer higher stress and so may fail in the future).

“Overheating is usually due to an air lock in the cooling system. To identify this, feel the top and bottom of the swim tank – there should be a difference in temperature. If not, find and unscrew the bolt sitting on top of the swim tank. This releases the air locked in the system. Overheating can also be caused by a coolant hose rupturing, a water pump failing, a fan belt shredding or at its worst, a head gasket failing.

“General wear and tear is the main cause of gear box and drive plate failure, so regularly service the gear box. When hitting an underwater object, it may affect the drive plate, but not necessarily the gear box. With a fouled propeller, loss of propulsion is commonly due to the prop being covered in debris such as weed or leaves. Clear by putting the engine into reverse.

“Prevent water ingress by keeping an eye on water levels within a craft and installing an automatic bilge pump. When there are stormy weather conditions and periods of heavy rain, water can seep into a boat, build-up and if not addressed, cause it to sink.”


RCR reminds this can occur anywhere if owners stray from the middle of the water course, cut a corner to take the shortest route or fail to check water levels before setting off.

Stephanie continues: “If your boat grounds, put on a life jacket and put the boat in reverse to see if it moves away from the obstruction. If this fails, identify the area of shallow water, by walking around the vessel testing the surrounding water depth with a boat pole.

“If the front of the boat’s grounded, move ballast that may be holding it down to the rear (gas bottles, the anchor, chains etc) and turn on the taps to empty the water tank (always at the front). This creates more buoyancy at the front and potentially lifts it a vital few inches. Half a ton of water can create a six inch difference. If it does clear, put the boat in reverse.

“If the boat’s grounded on one side, it’s a similar scenario; move anything that’s weighing it down in this area to the opposite side. Be cautious however, as if over-balanced, the vessel could list and take on water.

“If people are on board, one person should take the helm and the remainder can rock the boat gently to see if the momentum moves it. If the rear of the boat’s aground and the propeller’s lifted (a rare scenario), the boat will probably need a tow. But this should only be undertaken by an experienced boater - we’ve had cases where the person towing has got into trouble and two boats have had to be rescued. Hire boaters will invalidate their insurance if they undertake a tow.

“Once the vessel’s free, check it thoroughly, particularly the hull, as this could have been damaged.”


sunken boat attended by RCR

The most heart-breaking scenario – a boat sinking – in many cases could have been prevented with a bilge pump. Cases included:

  • Water ingress due to outlets close to the water line/leaks causing vessels to sit lower in the water
  • Water ingress via redundant air vents, caused by flood water and high winds
  • Leak from tank/shower pipes, bowl thruster pipes, water pumps, stern tube seals and stern glands
  • Incorrectly fitted and unsecure weed hatches/broken weed hatch seals
  • Too tight ropes and rising water levels allowing water to seep in
  • Caught on lock cills

lock cills

These below-water protrusions, positioned close to the top gates of most locks, catch many people out. Stephanie advises: “If travelling downhill in the lock chamber and the stern, ie rudder, gets caught on the cill, when the water recedes only the boat’s bow will lower with the water level, leaving the stern raised up. Sinking or capsizing can happen in seconds.

“If the stern is caught, close the bottom gate paddles to stop the water receding further and slowly open the top gate paddles to refill the lock. To stay safe in a lock, position the boat centrally and where possible keep the engine running with a centre line to hold it in position whilst tying off.

“A boat travelling uphill can equally get its bow stuck on a projection under the top gate – causing the stern only to rise with the water level. If this happens, close the top gate to prevent the lock filling and open the bottom gate paddles to allow the water level to fall.”

rcr logoTo find out more about River Canal Rescue go to their website check out their Facebook page call 01785 785680 or email