Peel Island (Teerk Roo Ra) lies in southern Moreton Bay between Cleveland and North Stradbroke Island, and its history is as much a draw as its reefs: it served as a quarantine station, an inebriates' asylum and, until 1959, a leper colony, and heritage buildings survive ashore. Horseshoe Bay, on its sandy southern side, is one of the bay's favourite weekend anchorages. marinelife.org.au lists it as a 2 m snorkel site with fringing reefs, fish and small critters, and the beached remains of the 189 ft bucket dredge Platypus, built in 1883 and beached at the island in 1930. Peel's fringing reefs are among the coral communities that survive inside Moreton Bay, with hard corals, soft corals and algae growing on rock in very shallow water.

They support small reef fish, damsels, wrasse and juveniles, with rays, turtles and the occasional dugong in the surrounding seagrass. The Platypus gives snorkellers an easy historical feature to explore close to shore. Visibility of 3-5 m is normal for the inner bay and improves at high tide.

The site suits families, snorkellers and newcomers on a boating day out rather than scuba divers – depths are too shallow for scuba to add much. It is a good introduction to Moreton Bay's marine life and history for those with access to a boat. Take care anchoring to avoid damaging coral and seagrass, and respect marine park zoning around the island.

Water temperatures range from about 18-20°C in winter to 26-28°C in summer in the shallow southern bay.

Boat access only – there is no ferry. Launch at Cleveland (Toondah Harbour/Emu Street ramps), Victoria Point or Manly and run about 5-8 km to Horseshoe Bay on the south side of Peel Island (15-30 minutes). Horseshoe Bay is a popular weekend anchorage; anchor on sand clear of coral and seagrass and use public moorings where available.

Snorkel from the boat or from the beach; the dredge Platypus lies beached on the island's shore.

Horseshoe Bay is sheltered from south-easterly winds but exposed to northerly winds, which make the anchorage rough. Visibility is typically 3-5 m and better at high tide, when clearer water floods in; low tide exposes much of the fringing reef. Rain reduces visibility for days.

Summer brings occasional jellyfish. Strong south-westerlies can also make the approach across the bay wet.

Snorkel along the edge of the fringing reef on a rising or high tide, then visit the Platypus remains near the shore. Scuba adds little in 2 m; snorkelling is the natural way to see it.

No regular dive operator; a popular private-boat anchorage for snorkelling. Occasional club snorkel trips.