Busselton’s Underwater Room Arrived by Tug

In March 2003, a concrete observation chamber was towed from Jervoise Bay to Busselton Jetty. Its destination was the seabed, eight metres below the water’s surface. The town’s new underwater room had to make a sea journey before it opened to visitors. [1]

The chamber was built by Doric. Once it reached Busselton, anchoring it required more than setting a heavy cylinder on the bottom: the state heritage record describes seventeen anchors drilled through steel casings into the seabed and secured with concrete. The jetty’s own guide describes the viewing windows as acrylic, 100 millimetres thick. [1–3]

An entrance still had to stand above the water. In July 2002, while the observatory was under construction, the Western Australian government announced $500,000 for its access building. That announcement anticipated completion by March 2003. March brought the tow; the official opening followed on 13 December. [1, 2, 4]

At the opening, Tourism and South-West Minister Bob Kucera credited the volunteer effort led by the late Allie Scott with driving the jetty’s restoration and new attractions. His announcement distinguished the interpretive centre at the shore end from the new offshore observatory. The concrete chamber stood about 100 metres short of the jetty’s outer end. [2]

What the windows revealed owed much to the structure overhead. The jetty’s guide explains that shade from the deck favours invertebrates on the piles, where sun-loving marine plants and algae would otherwise dominate. Sponges, sea squirts and soft corals occupy these submerged supports. The observatory brought visitors alongside that growth without taking it out of the bay. [3]

The guide’s tour descends from the intertidal zone to four bottom windows looking beneath the jetty. There, even pieces knocked off the structure by winter storms have a role: debris on the seabed provides shelter for animals living near the bottom. [3]