Meet the site
Racecourse Bay lies immediately west of Port MacDonnell, and the Marine Life Network lists it alongside the breakwater as the town's limestone reef option, at 2-5 m. It gives a more natural reef dive than the harbour, at the cost of more exposure.
The reef is low, ledged limestone with brown algae and kelp, sand gutters and small overhangs. Expect wrasse, sweep, leatherjackets, magpie perch, old wives and small reef fish, rock lobster in the ledges and the usual southern invertebrates – sea stars, urchins, sponges and abalone. Seadragons are possible in the weed. The shallow depth gives plenty of light on sunny days and makes it a good snorkel, but surge is felt all the way down.
The Port MacDonnell coast is also the heart of the lobster industry, and the rocky shores east at Cape Northumberland shelter lobster and little penguins. There is little formal dive documentation for Racecourse Bay itself, so it is best treated as an exploratory, calm-day site; talk to locals or the Mount Gambier dive shop for current entry points. It suits confident shore divers and snorkellers looking for easy reef close to Mount Gambier, and pairs well with a breakwater dive on the same day. Because there is no local dive shop in Port MacDonnell, fill cylinders in Mount Gambier before driving down, and check the swell forecast rather than relying on the view from town – the harbour can look calm while the open bays are still surging. Autumn mornings with light northerly winds are the pick. Snorkellers should stay close to the beach and away from any rip channels.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
Racecourse Bay (Port MacDonnell) is recorded as Reef in Limestone Coast. The listed access is shore. 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.
- Water movement
- Ask how swell and local exposure affect the proposed entry, exit and route.
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 Racecourse Bay (Port MacDonnell) 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 Racecourse Bay (Port MacDonnell) 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
Wrasse, sweep, leatherjackets, magpie perch, old wives, rock lobster, abalone, urchins, sea stars, kelp; seadragons possible
Location
A bay just west of Port MacDonnell with shallow limestone reef, dived from shore in calm conditions.
Facilities nearby
Roadside parking only; services in Port MacDonnell. Fills in Mount Gambier.
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.auen.wikipedia.orgRecord updated 26 Sept 2026. Source claims are being reviewed.