Blue Holes

Four openings in the reef top drop into a single vaulted chamber the size of a cathedral nave, where descending divers watch their own bubbles rise through columns of blue light. The cavern's windows exit onto the outer wall around 25–30 m, and most dives drift from there along the reef toward Blue Corner, collecting sharks and turtles on the way. A side chamber known as the Temple of Doom holds the bones of turtles that lost their way; it is a genuine cave, silty and dark, and belongs only to trained cave divers with local guides.

その瞬間のために: Light shafts through the skylights; the arched exits onto the wall; the drift continuation to Blue Corner on the right tide.

地形: Limestone cavern with sand and rubble floor, opening through arches onto the outer wall

流れ（カレント）: Sheltered inside; current picks up on exiting the wall toward Blue Corner.

エントリー: Drop through one of four skylights in the reef flat — a few meters deep — into the shared cavern below.

危険生物・リスク: Overhead environment by geometry even where light remains visible; do not enter the Temple of Doom side cave without cave training and a guide.

保全: Buoyancy discipline protects both the cavern walls and the divers below you in the light column.

ナイトロックス: ここでは効果的です——このエリアのプロファイルは、ナイトロックスが無減圧潜水時間を有意に延ばせる水深帯にあります（適切なトレーニングを受けていることが前提です）。