The William Pitt was a steam dredge that ended its working life as a breakwater in Canoe Bay, the small inlet on the north-west side of Fortescue Bay. It was launched in Bristol in 1904 as the Andre Reboucas, later worked on the construction of the Hobart Bridge and in Devonport, and was deliberately sunk across the mouth of Canoe Bay on 1 July 1953 to shelter the fishing boats that used the inlet. The hull is so shallow that parts of it break the surface at low tide, and it is best known as a snorkel site, though scuba divers enjoy a slow, shallow poke around it.

The Marine Life Network guide describes a submerged dredge hopper in 2-4 m with anemones and the propeller still visible, and notes cormorants, trumpeter, rock cod and conger eels. Decades underwater have turned the steel into a reef: the plates are covered in weed, sponges and jewel anemones, fish shelter under the hull, and cormorants perch on the exposed structure. It is a photogenic site, especially with the rusting frames rising out of the calm water against the forested hills.

Canoe Bay also has a history as a fish works that operated until the early 1970s, and remnants of the fishing industry can be seen ashore. The wreck is a pleasant excursion for campers at Fortescue Bay, combining a coastal walk with a snorkel, or a short kayak paddle for divers. It suits everyone from children with a mask and snorkel to photographers, and there is no current to contend with.

Drive to Fortescue Bay (Arthur Highway to Taranna, then 12 km of gravel on Fortescue Road; park pass required). From the Fortescue Bay day-use area walk the Tasman Coastal Trail north towards Canoe Bay, about 4 km and 1-1.5 hours each way through forest. Carrying dive gear this far is hard work, which is why most people snorkel the wreck; divers usually bring kit in by kayak or small boat from the Fortescue Bay ramp (about 5 minutes).

Canoe Bay is a very sheltered inlet on the north-west side of Fortescue Bay, protected from almost all directions; only a strong easterly pushing swell into Fortescue Bay affects it. Because the wreck is so shallow, the main factor is visibility, which is best on calm, sunny days after a period without easterlies. The site can be snorkelled year-round; low tide exposes more of the structure.

Enter from the beach and swim out to the wreck, which is visible from the surface. Circle the hull, look over the hopper and propeller and inspect the anemone-covered plates, then check the surrounding rocks for conger eels and rock cod before returning.

No dedicated operator trips; visited by snorkellers and divers camping at Fortescue Bay, by kayak and small boat.