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  Unit 7, 89 Erindale Road, Balcatta, Perth, Western Australia, 6021

Key Biscayne Oil Rig

Key Biscayne Oil Rig

On Friday 1 September 1983, the jack-up rig Key Biscayne was under tow off Lancelin, Western Australia, by two offshore supply vessels, Lady Sonia and Atlas Van Dieman, bound for Cockburn Sound from a drilling location off Darwin. Gale force winds were causing rough seas and a heavy swell.

At 0644, the tow line to Lady Sonia parted and attempts to pass a new tow line were unsuccessful.

During the day, Key Biscayne settled by the stern and developed a starboard list, so that seas started breaking over the deck. Therefore, all 52 persons on board the rig were evacuated by helicopter, this being accomplished by 1620.

At about 1840, the tow line to Atlas Van Dieman also parted, shortly after which Key Biscayne sank in 41 m of water, in a position 10 miles off Ledge Point. ( GPS location as 31° 09.89 S , 115° 11.81 E approximately 16 km from the coast and 20 km Southwest of Lancelin.)

The absence of “insurance” towing equipment and a marine crew aboard Key Biscayne resulted in the failure to connect a new tow line to Lady Sonia.

The break in the tow line resulted in the loss of directional control over the rig, allowing the rig to wallow in the heavy seas and swell.

Sea water entered the aft section of the rig by way of the shale shaker return line, flooding the mud pits and pump room, and later other compartments as the rig settled lower in the water, causing a loss of stability and eventual capsize. (This an excerpt from the Australian Marine Safety Bureau)

It is a rumored that a safe is still inside the wreck and has many thousands of dollars of diamonds and other treasures. Nothing like a buried treasure story to stimulate interest!

The Dive

Key Biscayne Oil Rig

Arguably one of the best dive sites on the west coast! We do 2 dives on the rig. Depths range from 24m to 42m. Best experienced on a 27% Nitrox mix. The structure lays on the sea floor which creates beautiful swim-throughs. Cray fish galore and resident Grey Nurse Sharks are just a couple of highlights.

The Trip

WHERE: We meet in Lancelin, which is 140 kilometers North of Perth, approximately 1 and half hours drive..

FORMAT: Two dives or One only decompression dive. (Conditions apply to decompression dives) – Divers must have appropriate decompression diving certification otherwise all dives are to be conducted within no decompression limits. Staff will be monitoring computers.


Two Dives and Charter fees

Divers need to supply all cylinders. Nitrox mixtures can be arranged through the shop however, you will need to organize these at least 3 day prior to departure. We return back to Lancelin at approximately 4.00pm.

Costs - $310.00

Divers are required to produce:

  • Dive computer
  • SMB or Safety Sausage & Whistle
  • Log book with recent deep dives, prior to booking
  • Deep Diver certification or the certification to the level they wish to dive i.e. decompression or re-breather. Technical/Decompression are limited to a 45 minute run time and dive plans to be submitted for approval prior to dive.
  • Proof of Enriched Air Nitrox Certification if using Nitrox
  • Diver must be medically fit to dive


  • Transportation to Lancelin and Equipment – normally groups are organized to share cars and transport costs, gear can be hired at either Dive shop the day prior.
  • Scuba Gear and 2 tanks.
  • Nitrox 27% – must be organised before the charter


Bookings can be made via the shop on 9240 6662 or pop in for a chat!

Disclaimer & Cancellation Policy

  • Payment in Full required on booking. Non refundable if cancelled within 72 hours of Charter.
  • Minimum numbers are required for charter to run. Diving Frontiers reserves the right to cancel or defer charter if minimum numbers are not met.
  • Dive charters are dependent on weather conditions and Diving Frontiers reserve the right to cancel or change boat/dive site if we believe there is a safety risk to passengers or crew.
  • Divers “MUST” present there Dive Certification or Temporary Dive Card on the morning of the charter to be permitted to board the vessel.