The coastline between Eaglehawk Neck and Waterfall Bay is one of Tasmania's best-known geological showpieces. At Doo Town the sea has drilled a blowhole through a cave roof, and a short distance south Tasman Arch and the Devils Kitchen chasm show later stages of the same process, where caves collapse into arches and then into open chasms. The reef off the Blowhole continues this story underwater with gutters, ledges and boulders on a gently sloping sea terrace.

The Marine Life Network guide lists the Blowhole Area at 15-20 m, with shore entry from the sea terrace and a gravel inlet, and a seaweed garden on the reef. Kelp and brown algae dominate the shallows, giving way to rock faces with sponges and small invertebrates deeper down. Wrasse, leatherjackets, magpie morwong and bastard trumpeter are common, rock lobsters shelter in the cracks, and weedy seadragons may be found along the weed edge.

It is not a regular charter site, which means it is quiet; the operators concentrate on Waterfall Bay a few hundred metres further south, where the invertebrate walls are more spectacular. The site's value is as a shore option for experienced independent divers staying at Eaglehawk Neck or Doo Town who want to dive from the car on a flat day. It requires careful judgment: the rock platform is exposed and the Blowhole's name is a warning about what swell does here.

Visitors who simply want to see the landforms can walk the short tracks between the Blowhole, Tasman Arch and Devils Kitchen, then dive the same geology in comfort from the dive centre boat.

From Eaglehawk Neck turn off the Arthur Highway onto Blowhole Road and follow it about 1.5 km to the Blowhole car park at Doo Town (toilets, food van in season). The Marine Life Network guide describes entry from the sea terrace and a gravel inlet beside the Blowhole; carry gear across the rock platform (a short walk) and pick the most sheltered gutter. Tasman Arch and Devils Kitchen are a further few hundred metres along Tasman Arch Road but have no practical shore access.

Boats from Pirates Bay reach the area in about 5 minutes.

The Blowhole faces east into the Tasman Sea and is only diveable from shore in genuinely calm conditions: westerly winds and swell under about 1 m. The Blowhole itself only 'blows' when swell is running, which is a clear sign to dive elsewhere; surge on the sea terrace makes both entry and exit dangerous. North-easterly to south-easterly swell closes the site entirely.

Best after several days of offshore westerlies in late summer and autumn.

Enter from the gravel inlet at slack sea, swim out along the gutter to the edge of the terrace, then descend along the reef to 12-15 m and explore the boulders and seaweed garden. Turn at half air and return to the same inlet; note an alternative exit before starting.

No scheduled operator trips; occasionally used by club and private divers. Eaglehawk Dive Centre boats pass the area en route to Waterfall Bay.