The jetty at Second Valley is small, but it and the seagrass around it have become one of the best-known leafy seadragon snorkel sites in South Australia. Guided snorkel tours bring participants to the jetty and seagrass beds in water no deeper than 5 m, and describe the site as renowned for the leafy seadragon along with blue devils, weedy seadragons and colourful fish. The Federation notes that the jetty is also used for dive training, and that its stairs have been repaired with an extension to support low-tide access.

Underwater, the piles carry algae, sponges and small invertebrates, and the sand and seagrass around the jetty hold the camouflaged animals that people come for. Leafy seadragons drift among the weed and seagrass edges, mimicking the fronds, and finding one takes a slow, patient search. Weedy seadragons, pipefish, small cuttlefish and various wrasse are also seen, and blue devils sit in any rocky holes nearby.

Being shallow and sheltered in easterly weather, the jetty is an excellent option for families, snorkellers and newly certified divers, and a good warm-up before the headland and caves or a swim to Lasseter's Reef. The stairs make entry and exit easy compared with the rock entries nearby. Seadragons are protected in South Australia: keep a respectful distance, never touch or chase them, and avoid lingering with bright lights or flash.

Keep clear of anglers on the jetty. The site is exposed to northerly and westerly swell, so check the forecast before driving down. On a calm summer morning, though, a slow hour here can be as rewarding as a far more demanding dive.

Second Valley is about 1 hour 20 minutes (92 km) south of Adelaide via Main South Road; turn right at the Second Valley sign and follow the road down to the beach. Park at the end of the access road (limited spaces; busy on summer weekends); there are public toilets and a changing room but no drinking water. The jetty is right beside the car park.

Enter from the jetty stairs, which have been repaired and extended for low-tide access, or from the beach beside the jetty. The seagrass beds are close by.

Second Valley faces north-west into the gulf. It is sheltered from southerly and south-easterly weather and best in easterlies, but it is very exposed to northerly through westerly winds and swell and is not diveable in a big swell. Summer and autumn mornings, before the south-westerly sea breeze, are most reliable.

Tidal currents are small inside the bay but can be felt off the headland. Visibility is often good in calm weather and drops after westerlies and rain.

Enter via the jetty stairs, explore the piles, then swim slowly over the adjacent seagrass at 2-4 m searching for leafy seadragons. Return to the stairs or beach.

Guided leafy seadragon snorkel tours run from the shore in season (90-minute sessions with accredited guides and marine biologists); Underwater Sports and other Adelaide shops use it for training and club dives.