Lynnies Leap is one of the sites the official Cocos tourism listing reserves for 'more experienced divers'. It is described as a special location where the reef top at about 14 m slopes away steeply to 40 m and beyond, and where 'varied currents' bring in 'a myriad of sharks' along with schooling fish and fusiliers. The published range for a recreational dive is 14–30 m.

The appeal is the action rather than the coral: on the outer north-western reef, west of Horsburgh Island, the current pushes nutrient-rich water up the slope and the fish respond. Clouds of fusiliers stream along the edge, and grey reef sharks, whitetips and blacktips – the three shark species Cocos divers see most often – patrol the slope, sometimes in numbers that justify the tourism site's description. Trevally and other pelagic fish hunt around the fusilier schools, and turtles are common.

The coral on the reef top and upper slope is healthy hard coral typical of the Cocos outer reefs, but most divers spend the dive watching the blue side. The currents are the reason the site is restricted: they are variable, can change direction and strength during a dive, and can carry divers off the reef or push them down the slope. Cocos Dive runs it as a drift with a live-boat pickup when the water is moving, and chooses the tide to suit the group.

Divers should be comfortable deploying a surface marker buoy and managing buoyancy in current without holding onto the reef. The name comes from local diving lore. Documentation beyond the official listing is thin, and precise details of the reef structure are best obtained from the guide's briefing on the day.

For experienced divers who want sharks and moving water, it is one of the most rewarding sites in the atoll.

Fly to West Island on the twice-weekly Virgin Australia service from Perth (usually routed via Christmas Island; allow 7–10 days on the islands to absorb weather and flight delays). Cocos Dive collects divers from West Island accommodation in the morning (pickup around 8 am, departure about 9 am) and runs its boats from West Island into the lagoon. Lynnies Leap is on the outer north-western reef west of Horsburgh Island, a short run from West Island past the sheltered north-western sites, but facing open water.

Live-boat drops are used because of current, and Cocos Dive schedules it only for experienced groups. No shore access.

Cocos has two seasons. The south-east trades blow steadily from roughly April/May to October, often 15–25 knots, which chops up the lagoon and pushes swell onto the eastern and southern outer reefs; divers are then kept to sheltered sites. The doldrum season (November to March/April) brings lighter, variable winds, flatter seas and the widest choice of outer-reef sites, and is the best time to dive, though it is also the tropical cyclone season and squalls pass through.

The north-western rim sits in the lee of the atoll during south-east trade winds, so these sites are often the ones that stay diveable when the trades blow; a strong westerly or north-westerly swell (uncommon, mostly in the doldrum season or with passing cyclones) closes them. Tidal flow through the Western Boat Passage near Horsburgh sets up currents along the reef edge, so dives are timed with the tide; visibility is best on the incoming tide when clear oceanic water pushes in. Lynnies Leap is known for varied currents that can change direction and strength during a dive, so it is timed for the gentler parts of the tide and run as a drift when flowing.

Live-boat drop onto the reef top at around 14 m, move to the edge and hold 20–25 m on the slope, watching the blue for sharks. Drift with the current rather than against it, keep the group tight and don't follow the slope past 30 m. Ascend on the reef top and complete the safety stop under a surface marker buoy for pickup.

Cocos Dive (Dieter Gerhard, West Island, operating since 1990) is the only scuba operator on the islands and the only way to dive this site. It runs seasonal two-dive day trips with lunch and a surface interval on Direction Island, maximum 10 divers per trip; sites are chosen on the day according to wind, tide and diver experience. Trips book out well ahead and courses are currently suspended, so arrive certified.