Banc du Geysir
(also Banc du Geyser
) is a mostly submerged reef
in the Mozambique Channel
's northeastern part, 125 km (78 mi) northeast from Mayotte
, 112 km (70 mi) southwest of the Îles Glorieuses
, and 200 km (124 mi) off the northwestern coast of Madagascar
, at .
The Banc is a dangerous oval-shaped reef 8 km (5 mi) long and 5 km (3 mi) wide that becomes exposed only at low tides, with the exception of some rock formations in the southern part of the reef. The rocks are generally 1.5 to 3 meters (5 to 10 feet) in height; the largest is South Rock, with a height of 8 meters (26 feet), similar to a boat under sail. In the eastern part of the reef there are some sandy cays, 1 to 3 meters (3 to 10 feet) in height covered with grass and small bushes. The entrance into the central lagoon is possible from a south-southeastern direction. There is an abundance of sea birds
, and the cays
are covered in tons of guano
The Geysir Reef was first known by Arab
sailors around the year 700, and was shown on some navigation-charts dated around 800. Around 1650 the reef was shown on Spanish maps as Arecife de Santo Antonio
. The current name was given on 23 December 1678, when the British vessel Geysir
ran on the reef.
The reef is claimed by France, Madagascar
and the Comoros
alike. From the French point of view, it is part of their Scattered islands in the......