Meet the site
Michaelmas Reef is a long, low limestone reef lying a kilometre west of Michaelmas Island, about 2 km long and half a kilometre wide. Marine Life Network describes it as a favourite of underwater photographers: the reef rises only a few metres from the sand, with kelp-covered shallows on top and ledges, crevices and undercuts around the edges covered in sponges, gorgonians and colourful smaller invertebrates.
Because the depth stays in a narrow band of about 14-18 m, the reef suits relaxed, unhurried dives, and the limestone is riddled with small holes and overhangs where nudibranchs, cowries, feather stars, crabs and small reef fish can be found. The kelp canopy on top shelters schools of old wives, sweep and bullseyes, while blue groper, harlequin fish, western blue devils and boarfish work the ledges. Occasional Port Jackson sharks and wobbegongs rest on the sand edges.
There is no signature feature here – no wall or wreck – and that is part of the appeal: it is a site for slow exploration and macro photography, and for newer divers who want a straightforward, shallow profile away from the more exposed Breaksea sites. It is often dived by South Coast Diving Supplies when conditions on the outer islands are marginal, and can be combined with the Cheynes III, which lies nearby off Michaelmas Island. Experienced divers may find it less dramatic than the islands, but the invertebrate life repays a careful look, and in winter the sound's resident humpback and southern right whales can sometimes be heard underwater while you dive.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
Michaelmas Reef is recorded as Reef in Albany & Great Southern. The listed access is boat (day trip). Confirm the actual meeting point, route and permission to visit; a map pin does not establish any of these.
Topics flagged by the stored research
These are questions prompted by the existing notes, not a verified or complete hazard assessment.
- Other water users
- Ask about vessel activity, exclusion areas and the agreed surface arrangements.
Historical access notes exist for this record, but have not been independently verified for current use. Request current directions from the operator or site manager rather than following an old entry description.
Questions, answered
Is Michaelmas Reef suitable for my certification?
The record lists Open Water. That does not establish suitability for every route or day. Share your training, recent experience and equipment needs with the operator and ask about the specific proposed dive.
Can I book Michaelmas Reef through YouDive?
YouDive is an independent research directory. Contact an operator directly to confirm whether it currently runs the trip, the inclusions and the booking terms.
What you might see
Sponges, gorgonians, ascidians, nudibranchs, cowries, feather stars, old wives, sweep, bullseyes, blue groper, harlequin fish, western blue devil, boarfish, Port Jackson sharks, wobbegongs, kelp (Ecklonia)
Location
A 2 km long, 0.5 km wide limestone reef about 1 km due west of Michaelmas Island in King George Sound, with kelp-covered tops and sponge-covered sides in 14-18 m.
Before you make plans
Conditions, access and operator schedules can change. This is a location guide, not a dive plan. Ask a local operator about current conditions and suitability for your training and experience.
Sources & further reading
marinelife.org.auRecord updated 26 Sept 2026. Source claims are being reviewed.
