Port Arthur's sheltered harbour serves as the departure point for vessels navigating the Tasman Peninsula's coastal waters, a route first charted during the penal settlement's operational years between 1830 and 1877. The cape raoul cruise port arthur departs from the same wharves that once received convict transports, now launching modern catamarans toward the Southern Ocean. Cape Raoul itself rises 300 metres above the sea, a dolerite monolith formed 170 million years ago when magma intruded into Jurassic sedimentary rock, then cooled into vertical columns that fracture under wave action into geometric platforms and sea caves. The Tasman Island lighthouse, visible 10 kilometres offshore during clear conditions, marked Australia's second-highest construction when completed in 1906. Keepers remained on the island until automation in 1976. Today the structure stands as the sole human presence on a granite outcrop surrounded by submerged volcanic sills and tide races that reach four knots during spring floods. Australian fur seals haul out on basalt shelves beneath the cliffs year-round, with populations peaking at 1,200 individuals during the October breeding season. Albatross and giant petrels follow the nutrient upwellings along the continental shelf margin, which drops to 200 metres within two kilometres of the coast. Cape raoul cruise port arthur tours traverse Waterfall Bay, where permanent springs descend 80 metres directly into the ocean, and round Tasman Island's southern cape, where dolerite columns stand in perfect hexagonal rows, each face measuring 60 centimetres across. The peninsula's geology exposes the contact zone between Permian mudstone and Jurassic dolerite, a textbook sequence studied by structural geologists since the 1960s. Weather permitting, vessels approach within 30 metres of the cliff base, close enough to observe the orange and grey lichen patterns that indicate high and low tide zones. Port Arthur's position on Storm Bay provides partial shelter from westerly swells, though operators monitor swell period and cancel departures when conditions exceed safe thresholds for passenger vessels under 20 metres. The three-hour circuit covers 45 kilometres of coastline, passing the convict-built jetty at Safety Cove and the coal mines at Slopen Island before returning through the sheltered waters of Mason Cove. Passenger capacity ranges from 36 to 48 depending on vessel, with enclosed cabins and open viewing decks standard across the fleet operating from Port Arthur's main wharf.