The Blue Hole is a diving location on the southeast Sinai, a few kilometres north of Dahab, Egypt on the coast of the Red Sea.
The Blue Hole is a submarine sinkhole, with a maximum depth within the hole of just over 100 m (328 feet). There is a shallow opening to the sea around 6 m (20 feet) deep, known as "the saddle", and a 26 m (85 feet) long tunnel, known as "the arch", whose top is at a depth of 55 m (181 feet) and whose bottom falls away as it reaches the seaward side to about 120 m (394 The Blue Hole is a hot spot for freediving because of the depth directly accessible from shore and the lack of current. There is a local legend that the Blue Hole is cursed by the ghost of a girl who drowned herself there to escape from an arranged marriage.
The Blue Hole at Dahab is believed to be by far the most dangerous and deadliest dive site in the world with some suggesting it to have claimed the lives of 130 to 200 divers in recent years. The reasons why this site is the most dangerous in the world are not clearly understood, with differing explanations given for its high death rate.