Siargao Island is composed of 48 islands and islets-politically divided into nine municipalities: Burgos, Dapa, Del Carmen, Gen. luna, Pilar, San Benito, San Isidro, Santa Monica, and Socorro.
Siargao Island contains the largest mangrove forest reserves in Mindanao, at Del Carmen. Long stretches of wetlands indicate a potential for commercial seaweed propagation. Siargao Island is greatly influenced by the winds and currents coming uninterrupted from the Pacific Ocean, intensified by the Mindanao current running westward through the Siargao Strait.
Siargao Island is situated at a coordinate of 9°52′N, 126°03′E.
Offshore, a classic tropical island lies protected within its surrounding coral reef with dozens of coconut palms dressed in the center circle of the island. Off to the right, well within the massive coastal reef, lies a shining white sand bar, (Pansukian, or Naked island) some 200 meters long. The tide of Siargao is diurnal with tidal curves typically present, especially on the east coast of the island.
The Island's Pacific-facing reefs are situated on the edge of the Philippine Trench, and the extremely deep offshore waters assure the ocean swells have undiluted power when they encounter the many coral and rock reefs. Siargao has excellent surfing conditions, particularly during the southwest "habagat" monsoon from August to November, when the prevailing wind is offshore.
The best known surfing wave on Siargao with a worldwide reputation for thick, hollow tubes is "Cloud 9". This right-breaking reef wave is the site of the annual Siargao Cup, a domestic and international surfing competition sponsored by the provincial government of Surigao del Norte.
The tide of Siargao is diurnal with tidal curves typically present especially on the east coast of the island.
It is the Surfing Capital of the Philippines.