Halkidiki — Sithonia

Four dive centres work the peninsula: Azure at Toroni, Nomad at Neos Marmaras, Oceanic at Nikiti and Ormos Panagias, and Nikiti Diving Center. A day is a mix of shore and boat. Korakas is a beach entry over sand that gives way to rock, with a 10 m maximum, and Deep Korakas also starts from shore, crosses a Posidonia meadow at 8 m and reaches rock at 24 m and a floor at 44 m. Offshore reefs such as Azapiko Nets and Volcano lie 300 to 350 m off the coast; at Azapiko the boat anchors in 5 m and the dive works along the reef to 20 m on the inner side or 35 m on the outer. Guided trips for certified divers run daily, and the offshore pinnacle at Vourvourou is a 20-minute boat ride.

Away from the beaches the bottom is rock. Manitari is a mushroom-shaped reef from 3 to 33 m, and Anemones City runs from 7 to 25 m under anemones and nudibranchs. Erica Cave is an open cavern entered at 12 m, about 40 m long and 10 m wide, where shrimps, crayfish and lobsters breed among sardines, groupers, morays and scorpionfish. Kartalia is a menhir-shaped rock 30 m tall reaching 60 m, with swim-throughs of 7 and 8 m, and the Kaminada chimney nearby is entered at 16 m and exited at 8 m. Below are the gorgonian reefs: yellow coral from 33 m at Nemesis, Pagona from 24 to 70 m, and Erica Gorgonians and Armatomenos from 27 and 30 m down to 90 m, yellow fans first and red ones deeper.

The shallow sites make this a straightforward place to learn or to bring a family: Destinika's gentle bottom is used for Try Scuba and Junior Open Water, and Korakas takes snorkellers and freedivers as well as divers. The deep sites are the reverse. Pagona, Erica Gorgonians and Armatomenos are labelled Deep Diver or Advanced, the Vourvourou pinnacle usually carries current and is listed for advanced and expert divers, and Nemesis runs from 7 m straight on to 70 m and Pagona from 24 m, so the plan has to stop where the certification stops, not where the reef does.

Three named spots are off limits to scuba: Toroni Castle, the Peristeronisi islet a short swim from Toroni, and Antikoufo are listed as protected marine areas where only snorkelling is allowed, and fishing is banned at the castle as well. The Ottoman Shipwreck is sold as an ordinary all-levels dive and as a snorkelling boat trip. Two smaller hazards: old fishing nets drape the Azapiko reef, where they now shelter fish, and the Kriaritsi rocks are scattered with sea urchins.