Melbourne Bommie Dives

Melbourne Bommie Dives by The Scuba Doctor

Bommie is an Australian term for an outcrop of coral reef or rock formation, often resembling a column, that is higher than the surrounding platform of reef or rock and which may be partially exposed at low tide.

Melbourne is fortunate enough to have some magnificent Bommie dive sites both inside and outside Port Phillip, not far from the heads.

Castle Rock

Bommie Dive Boat access
Crayfish Dive Site Open Water Rated Outside Port Phillip Bay Reef Dive Site

Castle Rock is located outside Port Phillip Heads in approximately 20 metres of water. It rises majestically out of a sandy bottom to around 12 metres on top. The walls of this bommie have many undercuts, splits and ledges and with jagged rock turrets on top it's easy to see how this site got its name! The rock is around 200 metres in circumference and can be circled once or twice in a dive. The fixed depth, lack of current and easy navigation makes this the perfect boat dive for newer Open Water divers.

Castle Rock is a wonderful dive with a wide variety of creatures from Nudibranchs to Seastars, numerous fish life including Blue Devils hiding under the ledges and a possible sighting of Seadragons to be found under and around the rock. There is even a slim chance of a Cray or two under ledges at the bottom, or in nearby reef.

Latitude: 38° 17.887′ S   (38.298117° S / 38° 17′ 53.22″ S)
Longitude: 144° 35.863′ E   (144.597717° E / 144° 35′ 51.78″ E)
Datum: WGS84 Google Map
Added: 2012-07-22 01:00:00 GMT, Last updated: 2018-01-23 19:57:57 GMT
Source: Peter Fear GPS (verified)
Nearest Neighbour: Deep Pinnacles, 250 m, bearing 287°, WNW
Depth: 12 to 20 m.
Dive only on: Ebb.

Christmas Bommie

Bommie Dive Boat access
Latitude: 38° 17.256′ S   (38.2876° S / 38° 17′ 15.36″ S)
Longitude: 144° 38.570′ E   (144.642833° E / 144° 38′ 34.2″ E)
Datum: WGS84 Google Map
Added: 2012-07-22 01:00:00 GMT, Last updated: 2018-01-14 16:30:08 GMT
Source: GPS
Nearest Neighbour: The Cathedral, 298 m, bearing 179°, S
-38 17.256
144 38.570
(WGS84)
Source: GPS

Corsair Rock

Bommie Dive Boat access
Advanced Open Water Rated Crayfish Dive Site Outside Port Phillip Bay Reef Dive Site Slack Water

The name Corsair Rock has sent shudders down the spine of many a seaman navigating Port Phillip Heads. The rock has been responsible for an extremely large number of shipwrecks and strandings. The rock itself is 6 metres in diameter and covered by 3 metres of water. The rock is located 600 metres west of Rock Beacon and can usually be identified by the swell breaking above it. When conditions are favorable the kelp-covered top of the rock may be seen from the surface. When conditions such as this exist diving around Corsair Rock is at its best.

Latitude: 38° 18.017′ S   (38.300283° S / 38° 18′ 1.02″ S)
Longitude: 144° 38.481′ E   (144.64135° E / 144° 38′ 28.86″ E)
Datum: WGS84 Google Map
Added: 2012-07-22 01:00:00 GMT, Last updated: 2018-01-23 20:00:26 GMT
Source: GPS
Nearest Neighbour: Australia RMS, 179 m, bearing 124°, SE
Depth: 6 to 30 m.
Dive only on: SWE.

Easter Bommie

Bommie Dive Boat access
Advanced Open Water Rated Crayfish Dive Site Inside Port Phillip Bay Subject to Shipping Slack Water

At the very Northern end of the Lonsdale reef systems lies Easter Bommie, also known as Sue's Grotto. No one really knows where the name originated, but everyone who has dived it knows it is a wonderful dive. Only divable at slackwater, the top is in around 16 metres on the Northern edge of the Bommie. Swimming North from the top, you will drop over the edge and you can descend to a maximum depth at the sandy base to around 27 metres. You can then follow the wall around to either the Southeast or the Southwest.

Crayfish are abundant in the Southeast. On a sunny day the light reflects from the sandy base making this site great for photography. Not dived as often as many other sites, so rather special. A great dive with lots of colourful soft corals and sponges and fans.

Latitude: 38° 17.017′ S   (38.283617° S / 38° 17′ 1.02″ S)
Longitude: 144° 38.611′ E   (144.643517° E / 144° 38′ 36.66″ E)
Datum: WGS84 Google Map
Added: 2012-07-22 01:00:00 GMT, Last updated: 2018-01-23 20:05:17 GMT
Source: GPS
Nearest Neighbour: Jims Hole, 49 m, bearing 168°, SSE
Depth: 16 to 27 m.
Dive only on: SWF, SWE.

Knawesome Bommie

Bommie Dive Boat access
Advanced Open Water Rated Crayfish Dive Site Inside Port Phillip Bay Reef Dive Site Subject to Shipping Slack Water

Knawesome Bommie, also known as Al's Bommie (after Alan Beckhurst), is located inside the bay on the top North East section of the Lonsdale Wall system. This large bommie rises from 40 metres to 22 metres with lots of other smaller scattered around it. Because it is located in the shipping channel this rarely dived site is teaming with marine life and a fantastic area for taking photographs.

Knawesome Reef is covered in soft corals sponges and fans, with some overhanging ledges and small caves. It is outside the Marine Park and Crayfish are known to be caught in the area. Other common fish species include the Southern Blue Devil, Magpie Morwong, Boarfish, schools of Pike and many others.

Latitude: 38° 17.152′ S   (38.285867° S / 38° 17′ 9.12″ S)
Longitude: 144° 39.374′ E   (144.656233° E / 144° 39′ 22.44″ E)
Datum: WGS84 Google Map
Added: 2012-07-22 01:00:00 GMT, Last updated: 2018-01-23 20:09:36 GMT
Source: Alan Beckhurst GPS (verified)
Nearest Neighbour: Awesome Reef, 101 m, bearing 17°, NNE
Depth: 12 to 40 m.
Dive only on: SWF, SWE.

Lonsdale Bommies

Bommie Dive Boat access
Crayfish Dive Site Open Water Rated Outside Port Phillip Bay Reef Dive Site

Approximately one kilometre from the Point Lonsdale Light and clear of the shipping channel, just outside Port Phillip Heads is an amazing area of bommies, or underwater rock formations. The strong current flow in this area has created a nutrient rich environment and subsequently prolific marine growth and the associated marine life. But it is the amazing rock formations that make this dive site special. A favourite spot for catching crays.

Latitude: 38° 17.983′ S   (38.299717° S / 38° 17′ 58.98″ S)
Longitude: 144° 36.730′ E   (144.612167° E / 144° 36′ 43.8″ E)
Datum: WGS84 Google Map
Added: 2012-07-22 01:00:00 GMT, Last updated: 2018-01-23 20:11:00 GMT
Source: Peter Fear GPS (verified)
Nearest Neighbour: Twin Bommies, 142 m, bearing 283°, WNW
Depth: 12 to 18 m.
Dive only on: Ebb.

Lonsdale Rock

Bommie Dive Boat access
Marine Park - No Fishing Outside Port Phillip Bay Reef Dive Site Subject to Shipping Slack Water

This site lies in the Port Phillip Heads Marine National Park. The park is made up of six separate marine areas around the southern end of Port Phillip: Swan Bay, Mud Islands, Point Lonsdale, Point Nepean, Popes Eye, and Portsea Hole.

See also, Parks Victoria: Port Phillip Heads Marine National Park, and Port Phillip Heads Marine National Park - Map (PDF 1.4 MB).

Latitude: 38° 17.960′ S   (38.29933° S / 38° 17′ 57.59″ S)
Longitude: 144° 37.420′ E   (144.62366° E / 144° 37′ 25.18″ E)
Datum: WGS84 Google Map
Added: 2012-07-22 01:00:00 GMT, Last updated: 2018-01-27 21:22:28 GMT
Source: GPS
Nearest Neighbour: 16lb Reef, 573 m, bearing 8°, N

New Deep Bommie

Bommie Dive Boat access
Crayfish Dive Site Deep Rated Outside Port Phillip Bay Reef Dive Site Technical Rated

New Deep Bommie sits in approx 42 metres water. If you swim along the West side first (with the Bommie on your left side) you'll come to high peaks rising up from 42 metres to 34 metres, which create gullies that divers can swim through. When you swim through the last one you'll come to an open expanse of rock usually inhabited by a large school of bull's eyes. At this point the diver can head North to the centre top of the Bommie and search for a cave opening at about the 34 metre mark. The opening leads to a swim through which is only a few metres in length with the Odd Wrasse passing you by. Or the diver can stay on the previous heading an encircle the entire Bommie where there are rich colors in the form of soft sponges dotted about the face of the Bommie and fish such as Wrasse, Horseshoe Leather Jackets, Sweep, plus more.

Latitude: 38° 19.079′ S   (38.317983° S / 38° 19′ 4.74″ S)
Longitude: 144° 34.000′ E   (144.566667° E / 144° 34′ 0″ E)
Datum: WGS84 Google Map
Added: 2012-07-22 01:00:00 GMT, Last updated: 2018-01-23 20:15:35 GMT
Source: GPS
Nearest Neighbour: J5 Yellow Submarine, 815 m, bearing 12°, NNE
Depth: 30 to 42 m.
Dive only on: SWF, SWE, Ebb.

Shortland Bluff Bommie

Bommie Dive Boat access
Advanced Open Water Rated Crayfish Dive Site Inside Port Phillip Bay Reef Dive Site Slack Water
Latitude: 38° 16.879′ S   (38.281317° S / 38° 16′ 52.74″ S)
Longitude: 144° 39.328′ E   (144.655467° E / 144° 39′ 19.68″ E)
Datum: WGS84 Google Map
Added: 2018-01-17 21:09:37 GMT, Last updated: 2018-01-23 20:24:49 GMT
Source: Peter Fear GPS (verified)
Nearest Neighbour: The Marbles, 284 m, bearing 273°, W
Depth: 18 to 20 m.
Dive only on: SWF, SWE.

Twin Bommies

Bommie Dive Boat access
Crayfish Dive Site Open Water Rated Outside Port Phillip Bay Reef Dive Site

Twin Bommies is exactly as its name would suggest, two large rock Bommies standing up from the 18 metre seabed just off Point Lonsdale outside of Port Phillip. The Bommies have a large community of fish life and are covered in bright soft corals and sponges. A great dive with lots of photo opportunities, not to mention the odd Crayfish or two.

Latitude: 38° 17.965′ S   (38.299417° S / 38° 17′ 57.9″ S)
Longitude: 144° 36.635′ E   (144.610583° E / 144° 36′ 38.1″ E)
Datum: WGS84 Google Map
Added: 2012-07-22 01:00:00 GMT, Last updated: 2018-01-23 20:30:58 GMT
Source: GPS
Nearest Neighbour: Lonsdale Arches, 83 m, bearing 237°, WSW
Depth: 12 to 18 m.
Dive only on: Ebb.

Total of 10 dive sites.


DISCLAIMER: No claim is made by The Scuba Doctor as to the accuracy of the dive site coordinates listed here. Should anyone decide to use these GPS marks to locate and dive on a site, they do so entirely at their own risk. Always verify against other sources.

The marks come from numerous sources including commercial operators, independent dive clubs, reference works, and active divers. Some are known to be accurate, while others may not be. Some GPS marks may even have come from maps using the AGD66 datum, and thus may need be converted to the WGS84 datum. To distinguish between the possible accuracy of the dive site marks, we've tried to give each mark a source of GPS, Google Earth, or unknown.

If you don't understand the differences between the different ways coordinates are given, plus how different datum come into play, you might find the article GPS Conversions by Lloyd Borrett (100 Kb, 5 pages, Adobe PDF) a useful read. It describes the problems associated with locating dive sites using a GPS receiver.

GPS latitude explained


Scuba Doctor Dive Map KML File

In the true spirit of making it easy to obtain, utilise and share the information, you can now Download/view the Scuba Doctor Dive Map GPS Marks (KML file | 220.98 KB | 05-May-2018) in the Keyhole Markup Language (KML) file format used to display geographic data in an Earth browser such as Google Earth and Google Maps.

Some marine GPS units can import the information from a KML file. For others you can use use a file translate program (e.g. GPSBabel) to convert the KML file into an import file format (e.g. GPX) supported by your GPS unit.


Please Help Us To Correct GPS Marks and Add More Melbourne Dive Sites

If you have have information about other dive sites you'd be happy to see added to the information available here, or any corrections and/or updates to the diving site GPS marks listed here, please feel free to Contact Us.

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