Meet the site
Michaelmas Cay is a small, vegetated sand island, about 1.5 hectares in area and rising only about 3.5 m above the sea, on the western tip of Michaelmas Reef. It is a national park and one of the most important seabird breeding sites on the northern Great Barrier Reef: Queensland Parks records up to 20,000 birds of 23 species in summer, dominated by sooty terns and common noddies, and the din and smell of the colony are part of the experience. Visitors may only land between 9:30 am and 3 pm and must stay within a roped area on the beach. Underwater, the site is a shallow, sheltered coral garden on the cay's protected western side, and Cairns Dive Adventures lists two snorkel areas, the Main Beach and the Outer Edge Wall, with depths of 1.5-12 m, no significant current and visibility of 10-15 m. Its most famous residents are giant clams, some thought to be over 60 years old, lying on the reef flat within an easy swim of the beach. Turtles are common, and the coral supports a good range of reef fish, parrotfish, wrasse, damsels, butterflyfish and anemonefish, with reef sharks sometimes seen on the edge. Ocean Spirit, which runs a sailing catamaran to the cay, holds advanced ecotourism certification for the trip and offers introductory dives from the beach as well as certified dives. The combination of easy, shallow diving, a bird colony and a sand cay makes it a classic family day. Experienced divers will find it limited in depth and scale, but it is a gentle and memorable introduction to the reef.
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 Cay is recorded as Reef in Cairns. 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.
- Current and timing
- Ask how the operator assesses the current window for the actual route. Historical tide notes are not a departure instruction.
- Other water users
- Ask about vessel activity, exclusion areas and the agreed surface arrangements.
- 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 Michaelmas Cay 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 Cay 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
Giant clams (some 60+ years old), green turtles, parrotfish, wrasse, damselfish, butterflyfish, anemonefish, reef sharks (occasional); sooty terns, common noddies and up to 23 seabird species on the cay
Location
Vegetated 1.5-hectare sand cay and seabird sanctuary on the western tip of Michaelmas Reef, about 40 km north-east of Cairns; snorkelling and diving on the protected western side.
Facilities nearby
Ocean Spirit vessel: toilets, lunch, snorkel gear, stinger suits; no facilities on the cay (national park)
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
cairnsdiveadventures.com.auparks.qld.gov.auoceanspirit.com.aureeftrip.comRecord updated 27 Sept 2026. Source claims are being reviewed.