BOATsmart! Canada
Knowledge Base

An Isolated Danger Buoy is used to mark a specific hazard or obstruction such as a rock, shoal or sunken island. The buoy is moored on or above the hazard, and will have navigable (safe) water all around it. 

It’s important to refer to a marine chart to determine the specific features of the isolated danger, such as it’s size, depth, and exact location. Never assume that the danger is small or easily avoidable- always navigate well clear of isolated danger buoys.

What does an isolated danger buoy look like?

• They are black in colour with a wide red band in the middle,
• They have a top-mark consisting of two black balls
• They may be equipped with a white flashing light