Flynns Reef is the Western Port-side shore dive at Summerlands, running between Flynns Beach and Farm Beach on the sheltered north-western face of Phillip Island's Summerland Peninsula. Scuba Doctor lists it at 2–8 m and describes it as suitable for novice to advanced divers, with visibility that can reach 20 metres, mild currents and diverse, colourful marine life – an unusually generous description for a shallow shore reef, and one that reflects the clean oceanic water that floods into Western Port past The Nobbies on every tide. The reef is basalt platform and boulder running parallel to the beach, with a sand and seagrass floor inshore and low ledges and bommies along its outer edge.

The local names attached to parts of it – Gordon's Mooring, Tennis Court, Tracy's Bommie and Coral Gardens – suggest how much time Phillip Island divers have spent here, and Coral Gardens in particular refers to the patches of sponge, soft coral, zoanthid and ascidian growth under the ledges that are richer than the depth would suggest. The fish are the Western Port shallow-reef community: wrasse, leatherjackets, cowfish, old wives, zebrafish, boarfish under ledges, Port Jackson sharks in season, with rays, flathead and sand-dwelling invertebrates on the seagrass, and there is a good chance of weedy seadragons in the weed line. Fur seals and little penguins pass through.

The dive is simple to navigate – north along the reef, turn, south back – and easy to enter, and the westerly aspect means it is at its best on easterly winds when the island's south coast is unworkable. Cat Bay and Right Point, a kilometre away, offer the same kind of reef with old jetty pylons. Flynns Reef is the pick of Phillip Island's western shore dives for new divers, snorkellers and photographers who want colour without depth.

From Cowes drive west on Ventnor Road (C473) for about 11 km; roughly 500 m past the Back Beach Road intersection turn into the Flynns Beach car park on the right. A track leads from the north-western end of the car park down to the beach – about 100–200 m carry over sand. Enter off the sand and head north along the reef towards Farm Beach; turn at the midpoint and come back the same way.

Right Point and Cat Bay are 1 km to the south-west along the same road.

Faces west across the Western Port entrance; best with calm seas and offshore easterly winds at high tide. Westerly and south-westerly swell refracts around The Nobbies into Cat Bay and Flynns Beach and produces surf – Cat Bay is a known surf spot in those conditions – so wait for a swell under 1 m and an easterly or light northerly. Tidal currents are mild inshore but the entrance streams run hard further out; visibility, which Scuba Doctor notes can reach 20 m, is best on the incoming tide in settled weather.

Diveable year-round; a good winter site on calm easterly days.

Enter off Flynns Beach, swim out to the reef edge at 3–5 m and follow it north towards Farm Beach with the shore on your right, exploring the ledges and weed line to a maximum of about 8 m. Turn around at the midpoint or half gas, return along the same reef with the shore on your left, and exit onto Flynns Beach. Sites named by locals along this stretch – Gordon's Mooring, Tennis Court, Tracy's Bommie, Coral Gardens – are all within the same swim.

No dive shop or dedicated dive charter is based on Phillip Island. Sites are dived by Melbourne clubs (VSAG, Melbourne University Underwater Club, Frankston/Peninsula clubs) and private boats launched at Newhaven or Rhyll; Mornington Peninsula shops (Dive Victoria Group, Portsea; The Scuba Doctor, Rye) run occasional Phillip Island days. Ocean Adventures Phillip Island (Cowes) runs seal-snorkel tours only.