The Canyon is a sand-bottomed indent into the Governor Island reef that begins about 20 m wide at its seaward (eastern) mouth and runs west into the reef. Its northern side is a vertical wall more than 15 m high with overhangs, and on the southern side are large boulders split by cracks and swim-throughs. The sand is about 37 m at the mouth and 33-35 m at the inner end, while the reef top is at 18 m or less.

The Combined Clubs Weekend guide calls it a valley between submerged cliffs and describes enormous, colourful sponges interspersed with ascidians, hydroids, sea whips, sea fans and anemones. The wall face is also covered in yellow zoanthids, and McFadyen noted yellow sea spiders, some with black leg bands, on the kelp, as well as crayfish and abalone tucked into the overhangs. Long-snouted boarfish patrol the canyon, and the kelp on the reef top is large and thick, moving with any surge. A garden gnome wearing a dive mask and a garden frog have been placed in the canyon by local divers and have become part of the dive.

The shape of the site makes for an easy, satisfying dive plan: in along one wall, across the boulders, and up a crack to the top. The deepest part is at the start, so divers can work progressively shallower. The Canyon shares its boulder section with Castle Cave to the south, and the two sites are often combined on consecutive dives.

It is a site for experienced divers with deep training who want a structured dive with walls, sponge gardens and swim-throughs in a single plan. Photographers like the vertical wall and its overhangs, and naturalists spend whole dives on the sponges.

Bicheno is on the Tasman Highway (A3), about 2 hr 15 min (180 km) from Hobart and 2 hr (160 km) from Launceston. Boats launch from the small ramp at The Gulch (Waubs Gulch), the narrow channel between Governor Island and the town foreshore off Esplanade; there is trailer parking beside the ramp and fishing co-op. The Governor Island sites are only 2-5 minutes' run out of the Gulch.

Tasmanian boat diving is almost always done as a live-boat drop and pick-up rather than at anchor. The Canyon is on the eastern side of Governor Island, 3 minutes from the ramp; Michael McFadyen gives the position as 41 52 08.6 S, 148 19 00.6 E (WGS84). Divers are dropped on the reef at about 18 m.

The Governor Island sites face east into the Tasman Sea, so easterly and north-easterly swell over about 1.5 m, or a fresh easterly/north-easterly sea breeze, makes them rough and surgy and can close the Gulch entrance. Westerly and north-westerly winds blow offshore and give the flattest seas; southerly swell wraps in and stirs the bottom, and a big southerly can drop visibility under 2 m for days. Winter (June-September) usually brings the clearest water (20-30 m) and most settled westerly weather; summer afternoons are often spoiled by the NE sea breeze, so dive mornings.

Surge from easterly swell can be felt in the canyon and the boulder cracks.

Drop onto the reef at about 18 m and swim to the ocean end of the canyon, where the sand sits at about 37 m. Follow the canyon west along its northern wall (33-35 m at the far end), cross to the boulder section at about 24 m with its cracks and swim-throughs, and use a crack system to climb back to the reef top for a safety stop.

Nitrox useful. Swim-throughs are short and open but avoid them in surge.

No confirmed full-time commercial dive operator in Bicheno as of 2026: the long-running Bicheno Dive Centre was reported closed (Michael McFadyen) although some tourism pages still list it - verify before travelling. Sites are dived by club boats (Tas Uni Dive Club, Tasmanian Scuba Diving Club, Leven Scuba Club), the annual Combined Clubs Weekend each June, and occasional trips from Launceston (Tasmanian Divers) and Hobart (Go Dive Tasmania) shops.