The Trident is one of the deep reefs on Go Dive Tasmania's list of Tasman Peninsula boat sites. The operator describes it as a deep reef with massive sponges and overhangs, in 20-40 m or more, for divers with Advanced or Deep certification. It belongs to the same family of deep sponge-garden sites that the Eaglehawk Dive Centre describes around both peninsulas: rock walls and pinnacles below about 25 m carpeted in brightly coloured sponges, soft corals and fields of sea whips, with huge schools of butterfly perch.

The overhangs add shaded habitat where jewel anemones, zoanthids and other invertebrates cluster, and rock lobsters and draughtboard sharks shelter. No public description of the site's location or layout exists beyond the operator's summary, so divers should expect a guided briefing on the day. It is a deep, short dive and best suited to divers with recent deep experience, good buoyancy and a conservative approach to gas and decompression in cold water.

Because Go Dive chooses sites daily according to weather, the Trident may or may not be on the plan for any particular trip. Divers who enjoy the sponge gardens at the Sisters or the Thumbs will find a similar experience here, often with fewer boats. Go Dive Tasmania's boat days include two dives with a boat crew, but equipment hire, cylinders and guides are extra and must be arranged through the Hobart shop the day before; divers must carry an SMB.

Nitrox is useful for this depth range if available. Ask at the briefing for the site's layout and plan the dive with your buddy around the operator's depth limits.

Boat access only with Go Dive Tasmania, which meets at The Adventure Lodge (5929 Arthur Highway, Taranna) at 7:30 am and launches from Eaglehawk Neck or Port Arthur depending on conditions, returning around 12:30 pm. The operator does not publish the site's position; it is chosen on the day when conditions suit a deep dive. Taranna is about 1 hour 15 minutes' drive from Hobart via Sorell and Dunalley.

The Tasman Peninsula faces the full Southern Ocean and Tasman Sea. South-westerly to south-easterly groundswell and strong easterlies are what cancel trips: operators generally need westerly or north-westerly winds with swell under about 1.5-2 m for the open-coast sites. Prolonged southerly swell pushes surge deep into the caves and gutters and churns visibility; after a big blow allow two or three days to settle.

Late summer and autumn (February-May) bring the most settled windows and the clearest water; winter can be glassy between fronts but fronts arrive every few days.

Descend directly to the reef at 25-30 m, explore the overhangs and the largest sponges, and begin the ascent at no-deco limits with a slow, controlled rise along the reef.

Deep Specialty required by operator for below 30 m.

Go Dive Tasmania – The Trident (20-40 m+, Advanced or Deep) on selected Tasman Peninsula boat days; two-dive trips $145-165.