Science of Silence

Why is there smoke coming from my yacht?

A smooth, enjoyable ride can quickly be brought to a halt if you notice smoke coming from your vessel.

Smoke is a clear indicator that something is wrong, and narrowing down exactly what the issue is can be achieved by examining the colour of the smoke emission. Depending on the colour, there could be a number of issues that suggest a problem with the engine and exhaust system:

White smoke.
There are a couple of reasons that cause yacht exhaust systems to emit white smoke, one of which can be overcooling. Low quality fuel or the incorrect fuel for your yacht’s engine can also lead to white smoke. It can also be the case that a clogged filter covered with algae can cause white smoke, or an issue with the engine cylinders, and sometimes, it’s a simple case of starting a cold engine that can cause a few small drops of fuel to create a white haze that will quickly dissipate. Because there are so many causes, it can be hard to know when to take your yacht in for inspection and when to carry on as normal, so it’s important to keep a note of how long the smoke lasts for, how thick it is and when it usually starts to appear to report to your mechanic to help establish the route of the problem.

Black smoke.
When yacht exhaust systems produce black smoke, it’s almost always to do with the fuel. Black smoke can indicate burnt fuel, or too much fuel in the tank compared with the amount of air in it. When you overfuel your tank, particles are emitted as gas or smoke instead of being burnt as fuel. Black smoke can also be an indictor of a poor air filter or an issue with the injector pump, but regardless of the cause, a solution for black smoke emission is normally straightforward.

Blue smoke.
In rare cases, yacht exhaust systems may spout blue smoke. This is indicative of burning engine oil, which needs to be seen to immediately as it is a major fire hazard. If engine oil is reaching a capacity in which it can be burned, this suggests something is wrong with the injector pump, as the oil and fuel shouldn’t be mixed. Blue smoke can also arise as a result of putting in too much oil in.

In any instance of smoke emission, make sure to keep detailed notes and seek professional, mechanical assistance as soon as possible to prevent any long-lasting damage to your yacht’s engine system.

If you’ve got questions about how to keep your engine and exhaust systems in peak condition, contact the experts at Halyard Ltd to have those questions answered.