The dolerite columns of Fluted Cape rise close to 272 metres from the water, cracked into vertical organ pipes when Gondwana began pulling apart roughly 180 million years ago. A Bruny Island Wilderness Cruise from Adventure Bay runs along the foot of that wall. Scale only registers at sea level. From the clifftop walking track the columns read as texture; from a boat they read as architecture, and the swell that carved them arrives unbroken across open water from Antarctica. Adventure Bay sits on the eastern side of South Bruny, a crescent of white sand sheltered by Penguin Island and the long arm of the cape. Furneaux anchored here in 1773; Cook followed in 1777, and Bligh in 1788. The bay has been a resupply stop for two and a half centuries because it offers rare shelter on an otherwise exposed coast. South of it, the land gives up entirely. Cliffs, sea caves and the rock stacks known as The Friars take over along the island's wilderness coast, and the road stops well short of them. That inaccessibility is what a Bruny Island eco cruise exists to solve. The Friars hold one of Tasmania's larger Australian fur seal colonies, several hundred animals hauled out on rock no walking track reaches. Bruny Island Wilderness Cruise from Adventure Bay tours run beneath albatross flight paths, past white-bellied sea eagles nesting in the cliff line, and into the surge cave known as the Breathing Rock, where compressed water exhales spray through a gap in the dolerite. Humpback and southern right whales use the same corridor on migration. Where the sheltered D'Entrecasteaux Channel meets the open Tasman Sea, currents concentrate krill and baitfish, and the food chain stacks up above them. Most of this coastline sits inside South Bruny National Park, and the waters south of Adventure Bay carry no jetty, no road and no lookout. There is one angle on the southern cliffs, and it is from the water. A Bruny Island Wilderness Cruise from Adventure Bay tour therefore functions less as sightseeing than as access — the only way to stand level with 272 metres of Jurassic rock, to see the seal colony without a telephoto lens, and to understand that the island's eastern shore is a thin, sheltered exception to a coast built entirely for the Southern Ocean.