Beachport Jetty is one of the great long jetties of South Australia – 772 m today, and more than 1.2 km in its prime – reaching out into Rivoli Bay from the middle of a quiet fishing and holiday town. It is primarily an anglers' jetty, famous for squid, whiting, salmon and mulloway, but it gives divers a sheltered, easy option on a coast where the open reefs are often unapproachable.

The dive is a classic South Australian jetty pylon dive. Rows of timber and concrete piles march out across sand and seagrass, and the encrusting growth increases with distance from shore: sponges, ascidians and algae, with small fish sheltering among them. Squid and cuttlefish are common – as the anglers attest – and rays, flathead and schools of salmon and mullet cross the sand. The marine life network notes that the Beachport area generally supports leafy seadragons and rock lobster under reef ledges, and it lists Beachport as good for night diving, when octopus, crabs and shrimps emerge on the pylons.

Depths are modest, increasing gradually towards the outer end, which makes it suitable for new divers, snorkellers and anyone wanting a long, gentle night dive. The length is the main logistical issue: carrying gear to the outer end is a serious walk, so most divers enter partway out. Published diver-specific information on Beachport Jetty is limited, so conditions and depths should be confirmed locally. It suits beginners, macro photographers and visiting divers caught by a big swell on the open coast.

Beachport is about 85 km (1 hour) north-west of Mount Gambier via Millicent, or 50 km south of Robe. The jetty is at the end of Beach Road in the town centre, open 24 hours and free. Park on the foreshore at the jetty base, gear up at the car and either walk in from the beach beside the jetty for the shallow inner section or carry gear along the deck to a ladder further out – the walk to the outer end is over 700 m, so many divers use a trolley.

Keep clear of anglers' lines on the deck and in the water.

Rivoli Bay is partly sheltered from the south-west by Cape Martin and the breakwater, so the jetty is diveable on many days when the open coast is not, but strong westerly to north-westerly winds push chop and swell into the bay and stir the sand. Visibility is best after several calm days and poor after storms or heavy seaweed wash-ups. The outer end is more exposed.

Summer afternoon south-easterlies create surface chop; mornings are best. No meaningful tidal current.

Enter from a ladder about midway along the jetty, descend to the sand at 4-6 m and zigzag outwards between the pylon rows, checking pylons for nudibranchs and seahorses and the sand and weed for rays and cuttlefish. Turn at half gas and return along the other side to the same ladder; safety stop on the pylons.

No local dive shop; divers self-organise. Nearest fills and hire at Dive Experience in Mount Gambier; Adelaide clubs occasionally run Limestone Coast weekends.