M & K Reef is a small, deep wall on the coast between Little Bay and Cape Banks, found in mid-2008 by St George Scuba Club member John Beddie and named after Michael McFadyen and his wife Kelly, whose wedding reception had just been held at the golf club on the cliff above. It is typical of the good deep reef that lies along this stretch and that almost nobody dives because the charter boats run straight past to Magic Point. The wall runs north–south with its top at about 22–23 m on the seaward side and its base at 27 m, and off the wall the bottom is rock and kelp sloping gradually to 30 m with a few small drops.

North of the anchorage a huge rock has come to rest against the wall to form a large but low swim-through, and near the anchor an isolated 'island' of reef creates a gully and a pinch point. The face has small cracks and overhangs all along it. Sponge and sea-squirt cover is dense and colourful, with some fine gorgonians, and the kelp on the slope holds weedy seadragons.

Fish are plentiful for a deep site: yellowtail, silver sweep and seapike in good numbers over the reef, leatherjackets working the growth, eastern blue devilfish in the caves and cuttlefish on the slope. At this depth the dive is a short one – around 20 minutes on air before deco – so the route must be efficient: north along the wall for ten minutes to where it turns east, then back over the top. It suits experienced deep divers with their own boat wanting an uncrowded first dive out of Botany Bay, followed by something shallow like Long Bay or Cape Banks.

Private boat only. From the Botany Bay ramps run out through the heads, round Cape Banks and head north about 2 km to sit off St Michael's Golf Club, using the club's water reservoir on the skyline as a mark; about 15 minutes from Cape Banks. Anchor on the GPS mark on the reef top at 22–23 m.

No charter operator dives this reef; it was found by St George Scuba Club in 2008.

An open-coast reef with no shelter; seas over about 1.5 m or a fresh north-easterly make the anchorage and the deep safety stop unpleasant, and current along this stretch north of Botany Bay is more frequent than off the Royal National Park. Because the shallowest point is 21–22 m the constraint is bottom time rather than weather – about 20 minutes on air – so use nitrox and dive it as the first dive of the day. Best visibility in autumn and winter after westerlies.

Descend to the reef top and drop over the wall to 27 m. Head north past the low swim-through formed by a huge rock leaning on the wall, checking the cracks and overhangs, to the point after about 10 minutes where the wall turns east – turn there. Come back south over the reef top, circle the small 'island' and its gully near the anchor, and look at the southern wall briefly before ascending the line with a long safety stop.

Nitrox 32 recommended.

Nitrox 32 recommended.

No regular charter – private boat or dive-club (St George Scuba Club) only