El Bajon

El Bajon is the Canaries' most famous single dive: a saddle-backed volcanic pinnacle off La Restinga whose twin peaks climb from deep blue to near-snorkel depth. The rock is ringed by life that reserve protection has let grow old: dusky groupers of real size, island groupers, thick schools of amberjack and barracuda wheeling off the towers, morays in every crack. In the warm months something bigger often passes: mobulas, tuna, occasionally a whale shark. Water clarity in the Mar de las Calmas routinely embarrasses the rest of Europe.

The moment you come for: Twin towers in blue water, large groupers, summer pelagic fly-bys

Topography: Twin volcanic towers rising from deep water to within about 8 m of the surface

Current: An open-water pinnacle: current can pick up mid-dive and dives are planned around it.

Entry: Short boat ride from La Restinga, El Hierro, inside the Mar de las Calmas marine reserve; dived when current allows.

Hazards: Current and open-water exposure; the summit tempts divers upward while the walls tempt them past plan depth.

Permits & rules: Daily boat and diver management applies within the reserve: book through local operators.

Conservation: Inside the Mar de las Calmas reserve; diving runs through authorized La Restinga centers under reserve rules.

Nitrox: Worth it here: profiles sit in the range where enriched air meaningfully extends no-stop time (with the training to use it).