Site Selection

Selecting the optimal site makes a huge difference

Selection Criteria

Careful planning goes into scuttling a ship, to prevent any harm to the environment and to maximise the potential of the wreck as a dive site. Proper site selection is crucial to ensuring that these two primary goals are met.

The site for the ex HMAS Canberra Reef has been selected on the basis that it satisfies the following criteria. The site:

  • must have geological characteristics suitable for the ship to settle with no impact on local reefs and other geological features;
  • must be devoid of sensitive marine habitats and have minimal impact on the local coastline;
  • must not impact on shipping lanes or navigational areas;
  • should be of a suitable distance from required commercial infrastructure to maximise commercial operation and diver attractiveness;
  • should be able to attract fish and increase local biodiversity;
  • should at an appropriate depth of water suitable for the experience level of the target market of divers;
  • should not be dangerous for scuba diving and have good visibility;
  • should not impact on other legitimate uses that may operate in the area; and
  • should have suitable currents.

There are strict rules and guidelines issued by the Environmental Protection Authority (EPA) for the placement of vessels as artificial reefs. Generally the vessel will not be placed on or near reefs or in an environment that will interrupt or affect marine growth.

Ideal Depths for ex HMAS Canberra
Ideal Depths for ex HMAS Canberra FFG-02

Site Selection History

Government Proposed Site

The Victorian Government authorities originally proposed a sink site for the ex HMAS Canberra designated in a wide area South of Barwon Heads.

The first major concern of VARS regarding this originally proposed site was the distance from Queenscliff, Portsea and Sorrento where the majority of dive charter operators are based. The site was significantly further than the majority of regularly serviced sites within, and adjacent to Port Phillip Bay and the Port Phillip heads area.

The turnaround time to this site would have exceeded the maximum two hour time required by local charter operators for cost effective operation.

Furthermore, the excessive distance would have significantly reduced diver attractiveness as well as posing an additional safety hazard if a major dive incident were to occur. Given that the Canberra is expected to be dived on a very frequent basis, this was a point which needed to be seriously taken into account as the probability of an incident would increase with frequency of use.

Members of the VARS team conducted a dive survey of this state government proposed site early in 2007.

The VARS survey team site report revealed serious concerns regarding depth and bottom composition.

To gain an understanding of site depths, a position was taken from the centre of the designated area. Depth readings in this location and to the Southwest were over 40 metres (131 feet). This was too deep for the certification and experience levels of the target diver market.

Another reading from the general centre was taken to the North with a depth of 32 metres (105 feet) recorded. This was an ideal depth, however the VARS divers reported the area was made up of vast reefs. It would therefore not be a suitable site for the scuttling due to both environmental considerations and the inability to allow the ship to settle on the bottom effectively.

Based on the above concerns the VARS committee strongly recommended that the Victorian Government authorities should choose an alternative site that would better satisfies the selection criteria.

VARS Original Preferred Site Location

VARS then identified just such a site.

VARS ex HMAS Canberra sink site survey team
Wednesday, 18th March 2007:
VARS ex HMAS Canberra
sink site survey team.
(L to R) John Lawler, Tom Wende,
Mick Jeacle, Mike Reed, Alan Beckhurst,
Barry Truscott. Photos: Mark Green.

An experienced Victorian charter boat operator advised VARS of a reef South West of the general area where the current J Class submarines and other dive site wrecks are located. If a sandy ocean floor existed to the North East of this reef, the site would be an ideal position for the ex HMAS Canberra sink site.

The turn around time of two hours to this dive site would meet the requirements of the commercial dive operators, safety concerns would be overcome and the all important requirements of the EPA would be met.

A VARS dive team was organised and set out on Wednesday, 18 April 2007, to locate the reef and survey the area.

The reef, which is around 6–7 metres high, forms a natural bowl covering an area of some 60,000 square metres. The existence of this bowl is significant as this would prodide great protection to the vessel from the prevailing south west winds and swells.

VARS survey divers get ready to dive
Mike Reed helps Mick Jeacle &
Barry Truscott get ready to dive.

A series of marker buoys were prepared and deployed, one out from the reef (which would be the approximate bow of the vessel), one in the centre, one north east (which would approximate the stern), one west and one east.

The VARS divers carried out a sea bed survey of some 240 metres (787 feet) along the line where the vessel would lay when sunk. (Note: This length exceeds the 140 metres (459 feet) length of the vessel, so as to ensure plenty of margin for optimal positioning.)

The great news is that the ocean floor was found to be SAND! This is an ideal bottom composition.

VARS survey divers finish the dive
Mick Jeacle & Barry Truscott
complete the dive at the shot line.

Furthermore the average depth of the site was found to be approximately 35 metres (115 feet). This will provide a dive site depth of around 18 metres (59 feet) to the bridge, 21 metres (69 feet) to the gun deck and 25 metres (82 feet) to the main deck.

Note: Approximate depths allowing 12 metre settling.

These depths were ideal for the target market of Advanced Open Water divers and wreck divers.

On this basis, it would be logical from all aspects of site selection and safety, that this position should be considered as the most suitable site for the resting place of the ex HMAS Canberra as an artificial reef and wreck dive site. VARS then proceeded to work towards getting this site accepted by the various government authorities.

ex HMAS Canberra Agreed Site Location

However, a number of state authorities had concerns about the site proposed by VARS being too close to shipping operational areas. Thus a hunt was conducted for an alternate site that would meet all of the requirements of all parties concerned.

Eventually, such a site was identified, agreed upon by all of the interested parties, and formally signed off on. See ex HMAS Canberra Reef Location for the full details.

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