Blue Hole (Dahab)

A reef-rimmed marine sinkhole north of Dahab on the Gulf of Aqaba, over 100 m deep, linked to the open sea by a shallow saddle and by a deep tunnel called the Arch whose top lies at about 52-55 m.

The Blue Hole is a submarine sinkhole in the reef about 10 km north of Dahab, on the Sinai coast of the Gulf of Aqaba. Its bowl drops to somewhere between 100 m and 120 m depending on the source. A shallow saddle at about 6-7 m connects it to the outer reef, and divers often enter via the Bells, a narrow chimney a short distance to the north.

At depth a tunnel called the Arch, about 26 m long, links the hole to the open sea; its top lies at roughly 52-55 m and the floor falls away on the seaward side. Although the overhead section is short, its depth puts it outside recreational limits, and the site has a long history of fatal accidents among divers attempting it without the right training or gas.

A Dahab dive centre describes the Arch as a technical dive only, to be done by certified technical divers on a planned decompression dive with mixed gases and redundant equipment.

The Blue Hole lies in the Abu Galum Protected Area and draws more than 110,000 visitors a year. In 2026 Egypt's Ministry of Local Development and Environment reviewed a plan to reorganise the site, regulate marine activities and cap visitor numbers; no implementation timetable had been published.

One of the Red Sea's best-known dive sites and the main documented overhead dive in Egypt. Its Arch is a short tunnel whose hazard comes chiefly from its depth.

Open-water entries from the shore over the saddle (about 6-7 m) or via the Bells chimney; the Arch is a deep tunnel to the open sea.