Claytons Wreck is at the southern tip of Nepean Island. Despite the name, both descriptions found treat it mainly as a reef dive: the Marine Life Network describes a rugged reef structure at 16 m, and Oceanatik lists it as a wreck, reef and rock site with a rocky bottom, hard and soft corals and a large array of marine life. Oceanatik calls it an unidentified wreck heavily colonised by coral.

The name is a puzzle. A 'Clayton's' is Australian slang for something that is not the real thing – from a 1980s advertising campaign for a non-alcoholic drink – and it may be that divers named the site because it is 'the wreck you have when you're not having a wreck'. That is speculation; the sources do not explain the name, and no shipwreck record for this position was found. Divers should not expect recognisable ship structure.

What the site offers is a rugged, photogenic reef on the exposed southern end of Nepean, with hard and soft corals and plenty of fish. The Nepean Island fauna recorded by Nigel Marsh at nearby sites includes Galapagos sharks, kingfish, trevally, goldribbon cod, black cod, morays and green turtles. The maximum depth of 16 m keeps bottom times comfortable.

Oceanatik rates it beginner-friendly and good for photographers. The southern tip of Nepean takes the full force of southerly swell, so it is dived only on calm days with northerly or light winds. It is a short run from Kingston Pier. Norfolk has more than 20 historic shipwrecks protected under Commonwealth law; if any wreck material is found here, it must not be disturbed.

Norfolk Island is about 1,450 km east of Brisbane; flights run from Sydney and Brisbane (about 2.5 h; check the current carrier). A hire car is essential. Norfolk has no harbour: Norfolk Island Diving's open boat is lowered by crane from Kingston Pier (south coast) or Cascade Pier (north-east coast), whichever is in the lee of the day's wind, and divers board from the pier steps once it is in the water.

For the Nepean Island sites the boat launches at Kingston Pier and runs about 1 km south to Nepean Island – a trip of 5–10 minutes. Nepean is a small, uninhabited island within Norfolk Island National Park; landing is not part of the dive.

Norfolk's south coast, including Kingston, Nepean Island and Phillip Island, faces the prevailing south-east trade winds and southerly swell, which are strongest from May to September. A south-easterly over about 15 knots or a southerly swell above 1.5–2 m makes the boat launch at Kingston Pier unworkable and the southern sites rough; they are dived on northerly or light-wind days, often in summer. Surge is felt in caves and gutters with any swell.

Visibility is typically 20–40 m and can exceed 40 m in winter. There are no stingers, and cyclones rarely reach this far south, though ex-tropical lows can bring big seas in summer and autumn.

Descend to the rocky bottom at 12–16 m and explore the rugged reef, looking for coral-encrusted debris among the rock. Circle back towards the island in shallower water for the safety stop.

Norfolk Island Diving (local instructor James and divemaster Mitch Graham) – small open boat craned in at Kingston or Cascade Pier depending on wind; runs part-time, mostly weekends, so book ahead by email (norfolkislanddiving@gmail.com).