27 February 2018

In a recent incident, the use of a sliding buoy system to retrieve an anchor may have caused the capsize of a recreational boat.

The operator of the 4.8 m boat had set a reef anchor about 500 m from the shore. As the weather deteriorated, the solo boater decided to retrieve the anchor and return to his launching place.

However, the anchor could not be freed and at the same time the propeller on the outboard motor was fouled by a slack portion of the anchor line.

The disabled vessel then began to take waves over the stern. The anchor line became taut and transferred weight on to the transom, which allowed more water to flood into the boat.

The boater tried to cut the line but was unsuccessful. Manual bailing could not keep up with the entry of water.

Pictured: A swamped vessel.

The boat then floated in a ‘basic flotation’ profile with the stern and motor under water and the bow just projecting above the surface.

Fortunately, the operator of the capsized boat was wearing an automatically inflating lifejacket which supported him in the water. He was soon recovered by other recreational vessels in the area.

The outboard motor showed signs of very heavy corrosion within 24 hours of the incident and is a complete loss.


  • Invest in a windlass or winch for the anchor if you have difficulty in raising the anchor by hand. MSV advises against the use of a sliding buoy system
  • Keep all slack lines well clear of the engine and propeller
  • Wear an appropriate lifejacket – you never know when you may be suddenly thrown into the water
  • Have a means of attracting the attention of local vessels – such as flares, smoke signals, whistle, torch etc.

Read more about safe operation