Meet the site
Alma Bay is the heart of shore diving on Magnetic Island: a small, patrolled Surf Life Saving beach in Arcadia with rocky granite headlands at each end, parkland, showers and a dive shop a few minutes' walk away. Pleasure Divers runs its guided shore dives and training here, and describes two distinct dive sites within the one bay – the Coral Gardens and the Canyons on the northern side. The bay floor slopes from sand near the beach to 5–6 m across the mouth, with the remains of an old jetty in about 1.5 m, a small rock wall and a central patch of reef and coral rubble. The real interest is along the headlands. On the northern point, large granite boulders stack into caves, gullies and swim-throughs that deepen to 8–10 m – the Canyons – with staghorn, plate and brain corals, sea whips and anemones. The Coral Gardens on the northern side have big brain, staghorn and plate corals and colourful soft corals at around 10 m. Fish and invertebrate life is excellent for a shore dive. Pleasure Divers counts more than 50 nudibranch species here, and the lists include coral trout, six-banded angelfish, unicornfish, honeycomb cod, squirrelfish, sweetlips, bannerfish, Moorish idols, fusilier schools, diamond fish, batfish, goatfish and moray eels. Blue-spotted, shovelnose and cowtail rays lie on the sand, epaulette and wobbegong sharks hide under ledges, painted crayfish sit in the cracks and green turtles are common. Large snails, cowries and Christmas tree worms reward slow divers. Alma Bay suits beginners and experienced divers alike, and at night the Canyons are a favourite. The bay is a green zone. Divers regularly find lost sunglasses, masks, weights and knives on the bottom, a sign of its popularity with swimmers.
What you might see
50+ nudibranch species, green turtles, blue-spotted, shovelnose and cowtail rays, epaulette and wobbegong sharks, coral trout, six-banded angelfish, unicornfish, honeycomb cod, squirrelfish, sweetlips, bannerfish, Moorish idols, fusiliers, batfish, moray eels, painted crayfish, Christmas tree worms, cowries
Location
Patrolled swimming beach at Arcadia with granite boulders, coral gardens and swim-throughs around its rocky headlands.
Facilities nearby
Patrolled beach, park, BBQs, toilets, showers, parking on Hayles Avenue; bus stop; Pleasure Divers dive shop nearby; cafes in Arcadia.
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
pleasuredivers.com.aunquec.org.aumarinelife.org.auRecord updated 26 Sept 2026. Source claims are being reviewed.