Arcos da Caloura

The dive starts at the top of the reef, a sheltered lava shelf around five metres down where the current usually runs weak. From there the route follows the lava flows to one of four entrances into a large cave, the deepest reaching sixteen metres. Inside, a school of white trevally often holds in open water while a dusky grouper works the narrow crevices along the walls. Around the cave mouth and the smaller arches nearby, the reef carries the usual south-coast cast: moray eels, rainbow and ornate wrasse, salema, parrotfish and dusky comber, with an octopus working the crevices on a slow pass. A 2014 trip report called it an easy dive through the lava arches, thick with life for how little effort it takes.

Arcos da Caloura is the cave dive of the Caloura zone. Panela, in the same protected area, is a single vertical pot-cave dropping to about eighteen metres; here the cave opens through four separate entrances into one wide chamber, reached from a reef top just five metres down. That shallow top is what lets the official tourism portal market the site for underwater photography, night diving, try-dives and snorkelling side by side, a combination not every overhead-environment dive can offer. A diver who worked it into a four-morning Azores Sub rotation called the trip unlike anything he had done before, heavy on lava rock, boulders and swim-throughs, and said he would dive it again.

The draw for photographers is the cave ceiling, thick with nudibranchs of several species and worth working slowly on the way to the entrances. The white trevally school and the resident dusky grouper both tend to hold in open water, clear of tight cover, giving a clean subject against the dark volcanic rock. Four separate entrances let in more ambient light than a single-shaft cave, useful for wide shots of the chamber before switching to macro on the ceiling.

Boat access only: about fifteen minutes from Vila Franca do Campo marina, the closer of the two departure points, or thirty minutes from Ponta Delgada. The site sits inside the Caloura and Ilheu de Vila Franca do Campo Resource Management Protected Area, 1,349 hectares of habitat protection, not a no-take marine reserve, so no diving-specific permit or fee applies beyond whatever your operator charges for the trip.1 No formal minimum certification is set for the dive; Open Water covers the reef top comfortably, and the cave's sixteen to eighteen metre entrances sit right at that certification's usual depth ceiling, so ask your operator how they run the overhead section. A moderately choppy sea has occasionally been reported at the surface, though the effect below is limited. June to October is the main season, and the site is diveable year-round, with a colder, quieter shoulder season from November to May.