Boat Harbour Point is one of the most popular shore sites on the north-west coast. The Marine Life Network guide rates it 5.5 out of 10 and describes Crystal Bay as sheltered and ideal for beginners on the main beach side. The eastern side runs from a 2 m cove to a cormorant roost in 8-10 m, with wrasse, juvenile zebrafish, sponges, nudibranchs, cup corals and zoanthids, and gorgonian fans, lace bryozoa and tunicates on the northern extension. The western side has 1-3 m boulders around Cascade Rock sloping to 12 m sand. Several leatherjacket species, banded morwong, zebrafish, long-snouted boarfish, bearded rock cod, bullseyes, herring cale and weedfish are recorded, and it is a good night dive.

The Leven Scuba Club lists three main dives here, including routes to Bird Island and finger reefs, with boarfish, trevally, zebrafish, squid, sea pens, rays and prowfish, and warns that good navigation is essential. Local divers typically combine two or three Rocky Cape and Sisters Island sites in a day, choosing the side of the cape that suits the wind and the state of the tide.

The Rocky Cape and Sisters Island area is, in the Leven Scuba Club's words, the best collection of dive sites on the north-west coast. The quartzite of Rocky Cape - some of the oldest rock in Tasmania - forms gutters, ledges, caves and bommies, and the tidal flow along Bass Strait keeps sponges, gorgonians, sea pens and bryozoans well fed. Michael McFadyen, diving here in February 2008, recorded 18-19 °C water and 20-25 m visibility, figures that surprise divers used to the east coast.

Rocky Cape National Park also protects Aboriginal cave sites and coastal heath above the water, and a Parks Pass is required for vehicles. The nearest hyperbaric chamber is the Royal Hobart Hospital, about four hours' drive away, so conservative profiles and oxygen on the boat are essential.

Boat Harbour Beach is 15 minutes west of Wynyard off the Bass Highway (1 hr from Devonport). Park near the surf life saving club; enter from the beach or follow the tea-tree scrub track from the change rooms to the point. Crystal Bay on the main beach side is sheltered and ideal for beginners; the exit over the wide, jagged foreshore is hard at low water.

The north-west coast faces Bass Strait: north-westerly to north-easterly winds and westerly swell make it rough, while southerly winds blow offshore and give flat seas - light airs and sunny days are relatively common from January to April. Easterly gales are common in the warmer months and close the eastern faces of Rocky Cape and Sisters Island. Tidal streams run along the coast (eastward on the flood), and several boat sites are only comfortable around slack water.

A rising tide gives a current-assisted return; the main beach side is sheltered.

Choose a side: east through the cove (2 m) to the cormorant roost (8-10 m) and the gorgonian-covered northern extension, or west past Cascade Rock's boulders sloping to 12 m sand. Navigation matters - note your route. Turn at a third of gas to allow for the swim back and a possibly harder exit, finish with a 3-minute safety stop at about 5 m if the depth allows, and exit where you entered unless an alternative exit has been checked beforehand.

No confirmed commercial dive operator on the north-west coast as of 2026 (older guides mention dive services in Wynyard and Devonport - verify). Sites are dived mainly by the Leven Scuba Club (Ulverstone), other north-west club members and visiting divers with their own boats; Tasmanian Divers (Launceston) runs occasional northern trips.