Long Canyon

Published depths run from about 5 to 25 m. The canyon itself works through that range as it twists, opening periodically into wider pools and chambers, and the coral garden outside the exit sits at the shallower end of it.

Roughly 15 to 20 minutes from entry to exit. It turns repeatedly and widens into chambers along the way before letting out onto the reef face, after which the dive continues over a coral garden.

No. The operating dive centre asks for experienced divers. The reason is the overhead: you are inside a fissure for 15 to 20 minutes with limited exit points, in passages narrow enough that a buoyancy error stirs silt and takes the visibility away from everyone behind you.

No. The site is not offered to snorkellers. The canyon is the whole dive and it is not something you can see or reach from the surface, and the site is only accessible on a dedicated speedboat excursion.

By speedboat from the Marsa Alam coast. Unlike most reefs in the area it is not on the standard day-boat rotation - it is sold as a dedicated half-day excursion, which is also why it stays quiet.

Yes, dive centres note that with enough gas remaining after exiting the canyon it is possible to reach the wreck of a cruise ship. Plan the reserve for it before you start: it is an add-on at the end of a dive that already spends 15 to 20 minutes in an overhead environment.

The occurrence record for this part of the coast is ordinary northern Red Sea reef fauna and matches the neighbouring Marsa Alam sites: sohal surgeonfish, bluespotted ribbontail ray, sailfin tang, common lionfish, masked butterflyfish, coral hind, giant moray and titan triggerfish. The draw here is the topography rather than the fish list.