Developments in lighthouse technology through the 20th century made the equipment much more reliable. By the time the Commonwealth Lighthouse Service was set up in 1913 it was possible for navigation lights to operate for long periods without attention. That is, they operated automatically, fuelled with cylinders of acetylene gas and using the highly reliable equipment made by the Swedish AGA company. In 1915–1918 the Commonwealth Lighthouse Service constructed a series of seven new automatic acetylene lights to mark the shipping route between Cooktown and the Torres Strait (Ramsbotham 1919). Some manned lightstations were converted to the automatic system and de-manned — examples include the light on Pipon Reef which was converted in 1915 (Ramsbotham 1919) and the Cape Bowling Green light, which was converted and de-manned in 1920 (Australian National Maritime Museum undated).
Figure — The lightstation site in 1954
Dent Island Lightstation, survey plan for proposed new quarters and tramway, 10 May 1954. This plan shows the two original keepers’ houses still in place, and a proposed new tramway terminating between them. To the north of the lighthouse tower is the engine room (containing the diesel generator set), and to the south of the tower is a fuel store. (Source: AMSA, drawing QS630).
Through the 1970s and 1980s, with further developments in the efficiency of solar-electric lighting systems, with the increasing importance of other aids to navigation such as radar, radio, depth sounders, and satellite global positioning systems (GPS), and with the drive for lower operating costs, the Commonwealth government proposed to automate most or all of its lighthouses. This was contentious (House of Representatives 1984). Among the vocal opponents were small boat operators who did not have radar or GPS and relied on the lighthouses and their keepers. (Buchanan 1994 gives a personal account of this period, from a Queensland lighthouse keeper’s point of view).
Ultimately, the scheme to automate and de-man the Commonwealth lights went ahead. In 1983 the light was automated. The land on which the lightstations stood was handed over to other government agencies, such as the various state national parks services, and AMSA arranged to lease back the small part of each site that was needed for the un-manned lights.
Figure — The lightstation (likely to date before 1995) Note the building on the far left which has since been removed. (Source: unknown photographer, photograph supplied by Hamilton Island Enterprises)
At Dent Island the light was converted to solar power in 1983 (AMSA 2004). The old Chance Brothers clockwork and kerosene optical apparatus was removed from the lantern room, and a Tideland ML-300 beacon installed on the 1925 mercury float pedestal from which the mercury had been removed. Power for the light came from batteries inside the tower charged by an array of solar panels. In 2010 a Sabik LED 350 beacon replaced the ML-300.
The lightkeepers remained at Dent Island, maintaining and monitoring the light, until the station was de-manned in 1987.
The responsibility for Lots 3 and 4 (on Crown Plan HR2019) passed to the Great Barrier Reef Marine Park Authority (GBRMPA) in 1994. Lots 1 and 2 (on Crown Plan HR2019) passed to the GBRMPA in 2003. AMSA leased two small pieces of land — a 58 m2 area around the tower (Lot 1 on Crown Plan HR2019), and a separate 669 m2 area on the edge of the cliff, retained as a possible site for a new replacement lighthouse and a helicopter landing pad (Lease A on Lot 2 on Crown Plan HR2019) (Figure 13).
The lighthouse tower remains the property of AMSA, which is also responsible for maintaining the small areas of land it leases from the GBRMPA. Lighthouse maintenance work is carried out by the AMSA maintenance contractor.
Maintenance of the former keepers’ houses and other ancillary buildings is the responsibility of the private lessee.
After the keepers left in 1987, the site was unoccupied for a time. In 1994 the private lessee appointed Rob Nichols as caretaker. He and his family stayed there until 1998. John Weymouth was appointed as caretaker in 1999 and was involved in considerable restoration work on the houses and ancillary buildings, funded by the private lessee.
In August 2009, after about three years of construction work, the Dent Island Golf Course Resort began operation. A section of the course occupies land leased by the private lessee from the Commonwealth (Lot 4, leased from the GBRMPA). Most of the golf course is on the state portion of the island (Lot 5, leased from the Queensland Department of Natural Resources and Mines). The resort includes an 18-hole golf course, a clubhouse, a maintenance compound, a marine landing facility, a heliport, services and a pump station. Future developments proposed include a 109-room five-star hotel and associated restaurant, lounge, bar, pool and tennis court, up to 38 villa sites and 172 two- and three-bedroom townhouses/apartments.
With the completion of construction and commencement of operations of the golf course, improved access to Dent Island Lightstation has been completed. Concrete roads for golf buggies and maintenance vehicles now service the developed state government owned part of the island. Access is available from the marine landing facility, the golf course helipad, around the 18 holes of the golf course and from the 12th fairway to the lightstation. The access distance of the concrete road from the 12th fairway to the lightstation is approximately 350 m, averaging 3 m in width. Access to the lightstation for works, maintenance and operations is now available in most weather conditions.