550 - 11/07 - Navigation warning - Philippines

A UK Club correspondent in the Philippines has warned of recent groundings on an uncharted reef at Dinagat Sound, Mindanao. Affected charts include British Admiralty chart 4475, United States chart 92110, and Philippine chart 4629.

The charted depth of the coral reefs and shoals (based on partial surveys conducted before 1930) is 27.5m but the reef creates an actual depth of 10m. Two ships have recently grounded on the reef with sailing draughts of 11.8m and 12.5m.

The nickel ore trade in the region has recently increased and shipments from Surigao in Mindanao (Southern Philippines) is loaded from barges at remote anchorages some distance from the port. Masters have chosen, upon departure, to transit Dinagat Sound, which is subject to strong currents and rip-tides, particularly during the monsoon period from September to February. Masters navigating these areas need to exercise extreme caution in order to prevent from grounding.

The image below illustrates the grounding area in relation to the Port of Surigao:


Staff Author