German Channel

You drop in at the south-west mouth of the channel rather than in the channel itself. Descending here, the reef slopes from about 10 m to around 40 m before dropping vertically into the blue. Tidal movement funnels a large volume of water through this relatively tight and very shallow cut, so which way the dive runs, and how much push there is, is decided by the state of the tide when you go in.

The cleaning station is the point of the dive: a sandy area with rocky outcrops where cleaner wrasses and butterflyfish nibble parasites from the skin of manta rays, sharks and large reef fish. Settle on the sand at a distance and wait rather than swimming at the animals. Manta numbers are highest during the mating season between December and March, and eagle rays, grey reef sharks, whitetips and impressive schools of fish work the same water. Tiger sharks have been observed here feeding on dead mantas.

The sand itself is worth reading. Fields of garden eels crane their heads into the current to feed, mantis shrimp scuttle across the floor, jawfish gawp up from their sandy lairs and shrimpgoby partnerships keep house together. Cuttlefish, nudibranchs and crocodilefish are commonly seen here too, so the site gives a photographer something to do on the days the mantas are slow to show.