Badger Head, west of the Tamar entrance, is rated 6 out of 10 by the Marine Life Network guide as the best crayfish prospect near Launceston, in 4-20 m. It describes Bass Strait fish, crayfish in the deeper areas and abalone in the shallows, but notes heavy fishing pressure and that the shallow areas are more scenic than the uninspiring deep bottom.

An echo sounder is needed to find the deeper reef. Recreational rock lobster and abalone fishing in Tasmania requires a licence and is subject to seasons, size and bag limits. As with all Tamar entrance sites, local knowledge of the tides is worth more than any written description, and a first visit with Launceston club divers is the best introduction.

The Tamar entrance is one of the most tidally energetic dive areas in Tasmania, and the Marine Life Network guide classes several sites here as category 4-5 because of current and shipping. Hebe Reef, a shallow reef at the mouth, has claimed many ships since the early 19th century, and its wrecks are protected historic sites. The flip side of the current is prolific filter-feeding life - sponges, bryozoans and ascidians - on any structure the water flows over.

Launceston divers have access to these sites within an hour of the city, and the sheltered Low Head shore dive is a regular training and club venue. The nearest hyperbaric chamber, however, is at the Royal Hobart Hospital about 3 hours' drive south, as Launceston General Hospital has none, so plan slack-water dives conservatively.

Low Head is at the eastern side of the Tamar River mouth, 5 km north of George Town and about 55 minutes (55 km) north of Launceston via the East Tamar Highway (A8). Boats launch at the Low Head, George Town or Kelso ramps. The Tamar is a commercial port (Bell Bay), so contact Port Control on VHF and keep out of the shipping channel when ships are moving.

Badger Head is west of the Tamar mouth, about 15-20 minutes by boat from the Kelso or Low Head ramps. A depth sounder is needed to find the deeper reef.

The Tamar heads are dominated by tide: large volumes of water flood and ebb through the entrance, and most boat sites can only be dived at slack water, typically within about an hour of the turn. North-westerly to north-easterly winds blow straight into the entrance and, against an ebb tide, create steep breaking seas over the bar and Hebe Reef. Southerly winds blow offshore and give the calmest water.

Visibility is best on the flood tide, when clear Bass Strait water enters; the ebb brings turbid river water, especially after rain. Badger Head faces north into Bass Strait; northerly and westerly winds make it rough.

Dive the shallow reef at 4-8 m for scenery, or use a sounder to locate deeper reef at 15-20 m for crayfish. 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.

Tasmanian Divers (42 Invermay Road, Launceston) runs regular local dives at northern shore sites including the Tamar region; Launceston clubs (Tas Uni Dive Club Northern Chapter and others) dive Low Head and the Tamar heads. No charter boat is based at Low Head; boat sites are dived from private boats launched at Low Head, George Town or Kelso.