Henley Jetty is one of the metro jetties on this region's list, but it is not described in any dive guide consulted. Fishing guides note that the jetty has only a sandy bottom along its length, which limits fish variety compared with jetties that cross reef or seagrass. Henley Square, a popular dining precinct, sits right behind the jetty.

The Henley coast also has a small place in local diving history: according to the Marine Life Network, South Australia's first attempt at a tyre artificial reef was laid off Henley Beach in about 10 m around 1970, but storms dispersed it, and the program was moved off Glenelg. The Grange Tyre Reef lies about 4 km offshore to the north-west. Underwater, divers should expect a shallow, sandy dive among the piles, with some growth on the timbers and small fish, crabs, and perhaps cuttlefish, octopus or rays, particularly at night.

Visibility along this stretch of coast is frequently poor because of fine sand and stormwater outflows, and the site is heavily used by swimmers and anglers. Henley Jetty is best regarded as a convenient calm-day snorkel for locals rather than a dive destination. Divers wanting a metro jetty dive will find more life at Glenelg Jetty or, much better, Port Noarlunga.

Anyone who does dive here should stay under or beside the jetty away from fishing lines and be highly visible to swimmers. A calm night after several days of easterly winds is the time most likely to reward the effort.

Henley Beach is about 20 minutes west of the Adelaide CBD. Parking is available around Henley Square and along the Esplanade (can be very busy on summer evenings). Enter from the beach beside the jetty and snorkel out along the piles.

There are no documented diver stairs, so plan to exit on the beach. Gear up at the car and walk across the sand; the carry is short. Swim out on the surface with a torch and surface marker buoy, and stay beside or under the jetty rather than out in the swimming area.

Entry and exit through small shore-break waves is easiest at mid to high tide.

These northern metro jetties sit on a shallow, sandy, west-facing coast. They are only worth diving in flat conditions after several days of easterly (offshore) winds; any westerly or south-westerly wind or swell stirs up the sand and turns the water milky, and the summer sea breeze usually arrives by early afternoon. The tidal range is small, but low tide leaves little water under the inshore half.

Visibility falls sharply after rain because of stormwater and river outflow along the coast. Night dives on calm evenings give the best chance of cephalopods.

Enter from the beach beside the jetty, snorkel out to the deeper outer half, then descend and work slowly along the piles with a torch, keeping well clear of fishing lines. Return along the other side and exit on the beach.

No dive operator uses this jetty; nearest shops for fills and advice are in Glenelg (Adelaide Scuba, The Dive Shack) and Edwardstown (Underwater Sports).