Blue Hole is a diving location on east Sinai, a few kilometres north of Dahab, Egypt on the coast of the Red Sea. The Blue Hole is a submarine sinkhole, around 130 m (462.5 feet) deep. There is a shallow opening around 6 m deep, known as "the saddle", opening out to the sea, and a 26 m long tunnel, known as "the arch", whose top is at a depth of 56 m (184 feet). The hole and the surrounding area have an abundance of coral and reef fish.
The Blue Hole is dived almost every day by recreational divers. Local dive centres take divers who are qualified to dive to 30m to do the site known as El Bells or Bells to Blue Hole. The entry is further along from the Blue Hole at an entry called The Bells. At 26m at the bottom of the Bells is a mini arch that should not be confused with the arch in the Blue Hole itself. Thedive is then a wall dive that finishes crossing the Blue Hole saddle at a depth of 7m. Recreational divers do not get to see the Blue Hole arch when doing the Bells to Blue Hole dive. The Egyptian Chamber For Diving & Watersports (CDWS) has a policeman stationed at the Blue Hole to ensure divers are diving with a certified guide to ensure safety procedures are followed.