HMAS Gascoyne Constructs Route Survey of Darwin Harbour

Royal Australian Navy Minehunter Coastal (MHC), HMAS Gascoyne, has been hard at work conducting Route Survey of Darwin Harbour over the past few weeks.

Route Survey is the exploration of a route to determine the nature of the seabed and the nature of any underwater objects that are detected. The data gained from such a survey enables the route to be cleared more quickly as required in support of operations as the majority of objects are known in advance, saving considerable time and effort.

In six days on task, Gascoyne not only achieved her initial intended tasking but also surveyed some additional substantial areas around Darwin Harbour that are being used or likely to be used by merchant and military vessels.

The Commanding Officer of Gascoyne, LCDR Aaron Cox, said Route Survey is a vital role for the Navy’s mine warfare community.

“Maintaining an up-to-date database of features and conditions in priority ports around Australia allows greater flexibility when conducting the planning of civilian and military units transiting strategic areas.

“The outcome of the survey was compared to previous surveys, so that changes to the seabed are detected and the information provided to the Mine Warfare Data Centre for analysis,” said LCDR Cox.

The Darwin Harbour Route Survey was conducted by running a series of pre-planned routes, detecting all objects on the sea floor with variable depth sonar.

The objects were then classified as ‘minelike’ or non-‘minelike’ and were positively identified with the ship’s Remote Operating Vehicles or by utilising the embarked Clearance Diving Element.

Data Dives were also conducted during the Route Survey to confirm the disposition of the seabed and the underwater environment.

Some previously identified objects in Darwin Harbour include shipwrecks, which were prosecuted by Navy Clearance Divers. Gascoyne’s Route Survey has now enabled a more exact location and height of the wrecks be passed on to the Australian Hydrographic Office to assist with updates to Darwin Harbour nautical navigational charts.

After the Route Survey, the crew in Gascoyne had a short, but thoroughly enjoyable visit in Darwin before heading home to HMAS Waterhen in Sydney.