The Leven Scuba Club lists several boat dives in the Port Sorell estuary, including an excellent site at Penguin Island with sponge gardens, nudibranchs and seahorses in 8-15 m. It notes that estuary dives are restricted to high tide. The estuary's tidal flow feeds sponges and other filter feeders, and its seagrass and sponge habitats suit seahorses. Details beyond the club's summary are not published, and the estuary is also popular with boaters and anglers, so fly a dive flag. Local knowledge from Leven Scuba Club members is the best way to get the most out of it, and first-time visitors should ideally dive it with someone who knows the site and the tide.

The central north coast between Wynyard and Port Sorell is the home water of the Leven Scuba Club at Ulverstone, whose site list is the main modern source for it, supplemented by the older Marine Life Network guide. The towns of Burnie, Ulverstone and Devonport sit right on the coast, so many sites are within minutes of a ramp or car park, but the reefs are generally low and weedy, visibility is often 5-10 m, and the coast is open to Bass Strait's northerly and westerly weather.

Devonport is the Spirit of Tasmania ferry terminal, which makes these sites the first and last dives for many interstate visitors bringing their own gear. There is no hyperbaric chamber in the north - the nearest is the Royal Hobart Hospital, about 3.5 hours' drive - so dive conservatively, especially on the deeper offshore sites.

Port Sorell is 20 minutes east of Devonport. Launch at Port Sorell or Hawley Beach and run into the estuary to Penguin Island. Estuary dives are restricted to high tide.

From the Spirit of Tasmania terminal at Devonport, all central north-coast sites are within about an hour's drive along the Bass Highway. North-coast ramps are often shallow and weedy at low tide, so time launches for mid to high tide and carry a sounder, radio and tide tables.

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.

Sheltered from swell but strongly tidal - dive at the top of the tide only.

Drop at Penguin Island at high tide, explore the sponge gardens at 8-15 m looking for seahorses and nudibranchs, and ascend before the ebb begins. Turn the dive at half gas (thirds where current or overhead sections are involved), deploy an SMB before surfacing for the live-boat pick-up, and complete a 3-minute safety stop at about 5 m where depth allows.

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.