Tea House Reef is the heart of Ricketts Point and, in The Scuba Doctor's phrase, Dive Central for the sanctuary. It is a broad shelf of Beaumaris sandstone directly off the yacht club and teahouse, cut by a series of parallel channels that run seaward from the reef top at about a metre to valleys at 3 m and finally to an outer edge at 4-5 m where the rock gives way to sand. The channels do the navigating for you, which is why it is the sanctuary's main training and night-dive ground and the first stop for most snorkel tours.

Fish are dense and tame after twenty years of protection: schools of juvenile snapper, zebrafish and old wives hang in the channels, dusky morwong and scalyfin patrol the algae, blennies fill the crevices and blue-throat wrasse follow divers hoping for disturbed food. Octopus are common under ledges, smooth stingrays and southern fiddler rays lie in the valleys and on the outer sand, and Port Jackson sharks turn up in winter. The rock is heavily grown with bryozoans, sponges, cushion stars and urchins and the seagrass edges carry pipefish and seahorses.

At night the reef changes character completely, with octopus, squid, rays and hunting fish everywhere. Facilities are the best of any bayside shore dive: ticketed parking within 100 m, toilets, a wheelchair ramp and accessible shower and toilet for disabled snorkellers, a cafe, and lighting. The cost is crowds: on summer weekends the yacht club beach is thick with snorkellers, training classes and families.

Go early, midweek or at night and it is as good a shallow reef dive as Melbourne offers.

From Beach Road, Beaumaris, turn into the Beaumaris Yacht Club car park (ticketed) or the teahouse car park just south-east of it. Walk down to the beach and north to the sand in front of the yacht club, a carry of 50-100 m; the sand is deeper and safer for entry and exit than the reef flat in front of the teahouse. Fin out toward the double markers, then turn left toward the reef.

Tea House Reef North and South are two names for the northern and southern halves of the same reef, separated by only 23 m on the published marks, and are dived as one site. Exit on the same sand.

Best with offshore light northerly to south-easterly winds. Avoid moderate to strong onshore southerly through westerly to north-westerly winds, which raise chop across the shallow reef flats, stir the sand and make the rock entries unpleasant; if you see white water over the reef from Beach Road, go elsewhere (Quiet Corner is the fallback). Dive just before high tide for the clearest water and enough depth over the reef top, which is exposed or awash at low water.

Visibility 3-8 m on a good day, better in winter, poor for two or three days after rain. No swell. Boat traffic outside the swimming zone is constant in summer, so tow a flag.

Enter on the yacht club sand, fin out to the double markers, descend to 2 m and follow the reef channels westward as they deepen to 3 m in the valleys and 4-5 m at the outer edge where reef meets sand, work along the edge in either direction for 15-20 minutes, then return up a channel to the markers and the beach. Turn at half gas. At night follow one channel out and the same channel back.

No commercial dive boat – shore site dived independently and by Melbourne dive shops for training and night dives (Scuba Culture in Cheltenham is the closest shop and uses the sanctuary regularly; Aquability and Melbourne Diving Services run club nights). Marine Care Ricketts Point runs guided snorkels in summer and Parks Victoria licensed tour operators run snorkel tours.