Castle Rock Boat Dive - Sunday 20th July

 Bommie Dive |  Boat access

Castle Rock | © Phil Watson

Depth: 12 m (39 ft) to 20 m (66 ft)

Level: Open Water and beyond.

Castle Rock is located outside Port Phillip Heads on the south-west, Point Lonsdale side in approximately 20 m (66 ft) of water. It rises majestically out of a limestone and sandy bottom to around 12 m (39 ft) 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 m (656 ft) 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.

But don't spend all of your dive time just exploring the base of Castle Rock. There is a lot of very interesting marine life to be found on the top.

Weedy Seadragon at Castle Rock
© Ian Scholey

Old Wives at Castle Rock
© Ian Scholey

Castle Rock is a wonderful dive with a wide variety of creatures including Nudibranchs to Seastars, typically on the top. You'll find Yellow Zoanthids plus numerous fish life including Southern Blue Devil, Old Wives, Boarfish, Dusky Morwong, Sixspine Leatherjacket, Scalyfin, Zebrafish, Bluethroat Wrasse, Senator Wrasse and Sweep hiding under the ledges. You can sometimes spot Weedy Seadragons under and around the rock. There is even a slim chance of a Southern Rock Lobster (aka Crayfish) or two under ledges at the bottom, or in the nearby reef.