Cova de sa Madona

Sa Madona is the big cave on the Andratx coast, opening in the cliff wall next to Cala Llamp. The mouth sits at around 7 m and the inner chamber drops to 25 m, about 20 m across, so there is plenty of room inside and it never feels tight.

It has two domes with air pockets where you can surface and breathe the cold air inside. Fresh water filtering down from land comes in at that upper level, and where it meets the salt water a halocline forms —along with its thermocline— blurring the view as if the water were streaked. It is one of those effects that catches you out the first time.

The feature it is named after is in the back right-hand corner: a carved Virgin placed inside the cave. Anemones and slipper lobsters are usually around it. Outside, the big boulders along the wall hold scorpionfish, octopuses, moray eels, groupers and barracuda.

Although the air domes take the edge off the dive, this is still an overhead environment: you go in with the centre's guide, in a small group, with a torch and without stirring the bottom, because suspended sediment ruins visibility for everyone behind you. The air pockets are old trapped air, not a breathable reserve to rely on.