Roe Reef is the workhorse of Rottnest diving: close to Thomson Bay, sheltered from the prevailing swell, and interesting enough for experienced divers while easy enough for new ones. It lies about a mile off the Bathurst Point lighthouse on the north-east corner of the island and is a classic piece of Rottnest limestone, eroded into small caves, crevices, tight swim-throughs and many little holes, with a prominent limestone arch on its western side that is the site's signature feature.

Depths run from about 6 m on the top to 16-18 m on the sand, and most of the dive is spent at 10-15 m weaving through the swim-throughs. Bucket List Diver describes maze-like passages and caverns suitable for all levels; the UWA Underwater Club notes tight swim-throughs and arches on the west side. Marinelife.org.au rates the fish life as very good, with colourful sponges and small invertebrates on the walls. Expect schools of reef fish, western blue groper, western rock lobster in the holes (the reef is outside the sanctuary zones and recreational lobster fishing takes place in season), wobbegong sharks resting under ledges, octopus, cuttlefish and stingrays on the sand.

Because it is quick to reach, charters often use Roe Reef as the first or second dive of a Rottnest trip, and it is a common training site for Advanced courses. It rewards slow diving: the small holes and overhangs hide a lot of life, and the arches make good wide-angle subjects. A torch is useful for peering into the caves.

Charter boats from Fremantle (Perth Scuba's Blue Destiny, Bucket List Diver) reach the north-east corner of Rottnest in about 40-50 minutes; private boats launch at Fremantle Fishing Boat Harbour, Woodman Point or Hillarys and run roughly 17-19 km across Gage Roads. Roe Reef lies about 1.5 km north of the Bathurst Lighthouse; charters drop divers on the reef or use a mooring, and private boats should anchor on sand beside the reef rather than on it.

Relatively sheltered from the prevailing south-westerly swell by the island, so it is often the site of choice when the south and west coasts are rough; Samphire notes it is best in low swell. Northerly and north-westerly winds and winter frontal swell make it surgy. Marinelife.org.au describes it as often having very good visibility.

Heavy boat traffic between Fremantle and Thomson Bay passes nearby.

Descend onto the reef top, head to the western side where the limestone arches are, and work through the swim-throughs and small caves at 10-15 m. Circle back along the reef edge, exploring holes for lobster and wobbegongs, and ascend from the reef top for the safety stop.

One of the most-used charter sites at Rottnest because it is close to Thomson Bay: Bucket List Diver, Perth Scuba and Dolphin Scuba run it frequently on Rottnest day trips; UWA Underwater Club and other clubs dive it from private boats.