Isolated Danger Buoy
An isolated danger buoy is moored on or situated above an isolated danger that has navigable water all around. For information concerning the danger, consult the chart. It may be used to mark natural dangers or obstructions, such as shoals or wrecks. Divided into thirds, the top and bottom sections are black, and the middle section is red. It may have two balls as a topmark.
This buoy indicates safe water. One side is white, the other is red. It is used to mark landfalls, channel entrances or channel centres. It may be passed on either side, but should be kept to the port side when proceeding in either direction.