Bare Island


A huge dive site covering 211,000 m2  (the island, with its 21,000 m2, it's only 10% of the submerged area). Mapping it has been an interesting project, with tidal currents, boat traffic and even boaters pulling me to the surface by grabbing my GPS. It took 20 dives (some of them with a sea scooter), 4 months and a total of about 200 hours. Thanks to all the divers I met in the carpark who with their interest and encouragement have kept me motivated, this map is for you too.

The map is available for download both as jpg and pdf.  The jpg is more handy being a smaller file but it lacks some of the benefits of the pdf, as described in the video below.

Please note: when mentioned, GPS locations are in WGS84 datum.

In case you wonder: fish are purposely not shown on the map to leave something to be discovered otherwise where's the fun? :)   And also to avoid overdiving species such as Weedy Seadragons, Red Indianfish, Sea Turtles, Eastern Blue Devils, just to name a few that are on the top of the list for most of us. Mapping a site may impact the distribution of the divers, but with this rule we are looking to provide the opportunity to explore more while avoiding targeted processions. And, at the end of the day, the size of this site and the currents will still limit the number of divers on the more remote locations.
41 tyres have been mapped though.

tidal currents

If you are not familiar with the SW side of the Island be aware of strong currents usually during the change of depth of the vast Botany Bay at West. Eastward going towards low tide and westward going towards high tide.

The current may be so strong to stop you from moving forward. That, coupled with the depth of 17-18 m, means running out of air quickly while still a long way from the exit and with boats over the head, so plan accordingly. A reasonable plan is avoiding the area in red unless it's slack water or unless you are doing a drift dive from one side of the island to the other. Sometimes the timing is different from expected, so just be present, assess the situation and divert to another zone if necessary.

Thanks to Michael McFadyen for his support in putting together this map and a reminder to check his website for an explanation of the impact of the tide.

How to make the most of the map

Below, a short video explaining some features. It's a living document, the site was surveyed in 10/2020-2/2021 but the sandlines and exposed low reef clearly change over time in consequence of currents and swell. When time allows, the map gets updated so I suggest not to save a copy on your device but rather check here for the latest.

The scale of all the bitmap is 1:1000, so if you use a photo editing tool each millimeter equals to a metre.

 The goal of the map is to improve the safety of the dive site by helping divers to plan the the start of the dive, the underwater itinerary and especially the end of the dive (how many times have we found ourselves way too far from where we wanted?). And with a good plan, adventurous divers can explore further. 

Important resources

If you are not familiar with this big site, use the map in combination with someone experienced and also check out the excellent Michael McFadyens Scuba Diving website for a wealth of information on the different dives at BI.

If you are curious about the marine life at Bare Island and want to discover some unusual facts about them, make yourself a gift and spend some time browsing the unique gallery of 1700 pictures by John Turnbull, the well know Marine Ecologist and Researcher at the UNSW. The gallery is publicly available on John's Flickr website.

Still from John, an interesting presentation summarising the ecosystem of Bare Island and why it matters in the controversial plan to build a cruise ship terminal in the nearby Yarra Bay.


I kept most of the names already in use, plus I did add some new names, like The Boomerang, as only now that we have a map we can actually appreciate the shape as seen from the sky. In case you wonder: Giulia's Pencils are named after my daughter, a talented designer living in Italy. Every time I find myself lost in the indistinct shallows with the pressure gauge on red, I find comfort in seeing those parallel cracks in the rock pointing to the way home, and send a thankful smile to my daughters from the distance.


To Greg Ryan and Michael McFadyen who have been helping me with their extensive knowledge of the site.For any question, comment or suggestion on the map, reach out to me over Facebook Messenger.

Happy diving!

Marco Bordieri

Photo #1 - the crossroad: left to the shortcut and right to continue West to first Cave. Located at X60 Y45

Photo #2: cave, South Bommie, located at  X100 Y128

Photo #3: anchor (lower center), North of the South Bommie, located at  X73 Y110

Photo #4: a classic scenery along most of the Eastern side at depths around 5 m: kelp and sandstone with holes hosting sea urchins. Located at X93 Y84

Photo #5: Finger sponges very common on the east side, here at the saddle between Bare Island and the Bommie. Located at X90 Y105

Photo #6: plough anchor on the Bommie. Located at X102 Y157

Photo #7: the big C on Isolated Reef 1. Located at X25 Y52

Photo #8: The "crumble" on the saddle between Bare Island and South Bommie. It can be used as a reference point for crossing.

Photo #9: an abandoned cray trap, SE of the South Bommie at X120 Y180

Photo #10: the concrete block with a chain at the back of the Corner Cave, at X43 Y52

Photo #11: one of the Great Sea Pen - Sarcoptilus grandis found on the sand East of the South Bommie, about 60 cm tall. They feed by filtering water, which is so apparent in this video