An engine stopping unexpectedly gets your attention very quickly. The important thing is not to let the mechanical problem become a boating emergency while you are trying to work out what has gone wrong.
Where the failure happens makes a considerable difference. Losing propulsion in open water may give you time to investigate. Losing it near a marina entrance, in a strong tidal stream or with commercial traffic nearby may require action almost immediately.
The first job is not fixing the engine. It is working out what the boat is going to do without it.
Look outside before looking at the engine
When the engine stops, resist the temptation to disappear into the engine compartment straight away.
Check your position, depth, nearby traffic and the direction in which wind and tide are moving you. If the boat still has forward momentum, you may retain steerage for a short time, but that will reduce as the boat slows.
Think a few minutes ahead. If you do nothing, where will the boat end up?
In open water, you may have plenty of time. Near a channel, shallow water, moored boats or a lee shore, securing the boat may need to come first.
Tell the crew what has happened and give people clear jobs if necessary. Keep somebody maintaining a proper lookout while you deal with the problem.
Decide whether anchoring will improve the situation
An anchor can buy valuable time if the boat is being carried towards danger.
It is not automatically the right response. You need suitable depth and holding ground, enough room for the boat to lie safely and confidence that you are not anchoring over an unsuitable area.
But if you are drifting towards shallow water, a shoreline or another hazard, getting the anchor down early can turn a developing problem into a much more manageable situation.
This is one reason to keep the anchor ready for use and to know roughly how much chain and warp you will need for the depth.
Once the boat is secure, you have more time to establish what happened.
Make a few sensible checks
Think about what happened immediately before the engine stopped. Did it cut out suddenly or lose power gradually? Was there an alarm? Had the temperature changed? Did you notice unusual vibration, smoke or a change in engine note?
Those clues are more useful than randomly opening lockers and moving switches.
Depending on the boat and your knowledge of its systems, straightforward checks might include the engine controls, emergency stop or kill cord, fuel supply, battery isolators and warning indicators.
If there is smoke, a smell of fuel, visible leakage or any suggestion of fire, do not keep trying to restart the engine. The same applies to serious warning alarms. An engine that has stopped following an overheating or low oil pressure warning should not simply be restarted without understanding why.
Repeated cranking can also flatten the battery, potentially affecting equipment you still need, including the VHF, navigation equipment and bilge pumps.
If a simple cause is not apparent, there comes a point when troubleshooting should stop. You do not need to become a marine engineer at sea. Keeping the boat safe and arranging assistance is more important than dismantling something you do not fully understand.
If the engine does restart, check the gauges and warning lights, listen for anything unusual and make sure it appears to be cooling normally before relying on it again.
Call for help while you still have options
There is little benefit in waiting until a manageable engine failure has become an emergency before telling somebody about it.
Depending on your position and the level of risk, you may need to contact a marina, harbour authority, towing service or the coastguard. If there is immediate danger, use the appropriate emergency procedure.
When making a call on the VHF, concentrate on the useful information: who you are, where you are, what has happened, how many people are aboard and whether you are anchored or drifting.
You do not need a detailed diagnosis of the mechanical problem.
It is also worth making sure more than one person aboard understands the basics of using the VHF. If the skipper is occupied elsewhere, somebody else may need to make the call.
A twin-engine boat still needs a plan
Losing one engine on a twin-engined Motorboat may leave you with propulsion, but the boat can handle very differently.
Manoeuvres that normally rely on using the engines against one another may no longer be available, particularly at low speed. Wind and tide can also have a greater influence during a marina approach.
Give yourself more room and avoid turning an engine problem into a difficult berthing situation.
It may be easier to arrange assistance or use a more accessible berth rather than attempting your normal berth with reduced manoeuvrability.
If you need a tow, prepare before it arrives
If another vessel is coming to assist, use the waiting time.
Put out fenders, prepare suitable lines and identify strong points that can safely take the load. Keep unnecessary people away from the working area and make sure nobody wraps a rope around a hand or stands where a loaded line could cause injury.
Agree the towing arrangement before lines are passed. The arrangement may need to change when entering sheltered water or approaching a marina.
If possible, speak to the marina before arriving. An easier berth or assistance from shore may remove the need for a difficult manoeuvre with limited control.
Once ashore, find out what happened
Getting safely back to the berth does not mean the problem has been solved.
If the cause was not obvious and properly resolved, have the fault investigated before relying on the engine again. Intermittent problems can be deceptive because everything may appear normal once the engine has cooled or the boat has stopped moving.
Think about anything that made the incident harder as well. Equipment that was difficult to reach, uncertainty over the boat’s position or problems communicating with the crew are all worth addressing before the next trip.
Know how your own boat behaves without power
How quickly a Motorboat loses steerage and how it lies to the wind will vary considerably between vessels.
In safe conditions with plenty of room, become familiar with what happens when your boat is taken out of gear. Notice how long it carries its way, when steering begins to disappear and how wind and tide affect it as speed falls.
Training on your own boat can also help you understand the characteristics of the vessel you actually use rather than relying on general assumptions about Motorboat handling.
It is equally useful to know where the fuel shut-off, battery isolators, bilge pumps and fire extinguishers are while you are comfortably alongside rather than searching for them when something has already happened.
An engine failure does not automatically mean an emergency. The priority is to stop the loss of propulsion creating a second problem.
Look at what is happening around you, work out where the boat is going and ask for help while you still have choices. You may not be able to fix the engine on the water, but you can do a great deal to keep the situation under control.
FAQs about motorboat engine failure
What is the difference between a Mayday and a Pan-Pan after an engine failure?
A Mayday is used when there is grave and imminent danger and immediate assistance is required. A Pan-Pan is used for an urgent situation affecting the safety of a vessel or person where there is not currently grave and imminent danger. The loss of an engine alone does not automatically determine which call is appropriate; the boat’s position and the developing risk matter.
Is a handheld VHF useful if the motorboat loses electrical power as well as the engine?
A charged handheld VHF with its own battery can provide an independent means of communication if the boat’s main electrical system is unavailable. It should be kept accessible and its battery condition checked regularly if it forms part of your emergency equipment.
What engine information is useful to keep aboard?
Keeping the engine make, model and other relevant identification details readily available can make it easier to describe the installation when arranging technical assistance. Manuals, service information and details of suitable consumables or spares can also be useful, provided they are stored somewhere accessible.
How can you reduce the risk of engine failure before a longer passage?
Routine servicing and pre-departure checks can identify many developing problems before leaving the berth. Pay attention to fuel condition, cooling arrangements, fluid levels, batteries, belts and anything that has behaved differently on recent trips, following the manufacturer’s requirements for your particular engine.
Should a single-engine motorboat have a more conservative passage plan?
The consequences of losing propulsion are worth considering when planning any passage, particularly where there are few places to anchor or obtain assistance. Allowing suitable margins, knowing where shelter is available and thinking in advance about what you would do after a loss of propulsion can give you more options if a fault occurs.