Lake Malawi

Diving here is organised around a beach rather than a harbour. Centres at Cape Maclear in the south and Nkhata Bay further north keep their kit a few steps from the water, and a day tends to run as a boat trip out to an island in the morning and a walk-in entry off the rocks in the afternoon. There is no tide to work around and no ocean swell, so the only thing that moves a plan is wind: the lake raises its own short chop when it gets up, and that decides whether the boat goes.

Underwater the ground is rounded boulders stacked down the slope, with gaps and caves between them and sand flats where the rock runs out. That boundary does the sorting. Rock-dwelling mbuna graze algae off the stone and are reluctant to cross open sand, which is part of why one headland can hold forms the next one along does not. Over the sand the cast changes again, including species whose males build and defend shallow display bowers. Ten metres of swimming takes you between two different faunas.

The signature dive is not a route but a stop. Pick a boulder field, get neutral, and stay put. Within a metre or two of your mask, males in breeding colour see off rivals, females hold broods in their mouths, and courtship runs in circuits that take minutes rather than seconds. Come back after dark and the slope has changed shift: the day fish are wedged into cracks in the rock, and catfish, kampango among them, hunt out across the open sand.

It suits divers who would rather watch behaviour than count big animals, photographers working macro and mid-range, and anyone travelling with non-divers, since the same shallows snorkel just as well. Nothing about it is demanding in any month, and the water stays in the twenties year-round; what changes is clarity, with September to November the window worth planning around and the rains early in the year putting silt in the water. Bilharzia is present in the lake, so ask a travel clinic about the usual post-trip treatment before you go.