Port Giles is a long, modern grain-loading jetty built in the 1970s to take bulk carriers, and for years it was one of the best jetty dives on the peninsula precisely because it reaches deeper water than the old nineteenth-century jetties. The structure runs a long way out into Gulf St Vincent, and the bottom slopes from a few metres at the shore to around 13-16 m under the outer section and loading berth. The Dive Shack notes that divers used to plan to reach the midpoint with half a tank, because the swim out is long and the depth steadily increases.

The concrete and steel piles are coated in sponges, soft corals, ascidians and hydroids, and the combination of depth and shade attracts more fish than Edithburgh. Boarfish, trevally, magpie and other perch, morwong, bullseyes and yellowtail school through the piles, while eels, seahorses and leafy seadragons have all been recorded. Blue swimmer crabs and cuttlefish are common on the sand.

The catch is access. The jetty is an operational Viterra facility, and diving, fishing and snorkelling from the jetty itself have been banned, so the traditional shore entry from the steps at the base is no longer available. The SDFSA now lists boat diving from the Edithburgh ramp as the way in, and even then divers must stay clear whenever ships are alongside or manoeuvring.

Consequently Port Giles is now a rarely dived site, visited mainly by locals and club members with their own boats on quiet days. For divers with a boat, it remains a worthwhile deeper alternative to Edithburgh, offering bigger fish, more depth and a different character to the shallow macro jetties. Treat it as an industrial site: be visible, fly a dive flag, and leave immediately if a ship approaches.

Port Giles is 8 km north of Edithburgh off the coast road (about 215 km from Adelaide). The jetty is an operational Viterra grain-loading facility, and signage now prohibits diving, fishing and snorkelling from the jetty itself, so the old walk-in from the steps is no longer allowed. Divers who visit do so by small boat launched at the Edithburgh ramp (about 15 minutes' run north), staying clear of the loading berth and never diving when a ship is alongside or approaching.

Check the current access status with Viterra and local dive shops before going, as rules have changed several times.

This coast faces Gulf St Vincent, so onshore easterly, north-easterly and south-easterly winds ruin it: 15 knots from the east stirs the fine sediment and drops visibility to a metre or two, and a strong south-easterly adds chop and surge. Westerly and south-westerly winds blow offshore and give the flattest, clearest water, best after a day or two of settled weather. There is no ocean swell inside the gulf.

Tides are modest (1-2 m, with 'dodge' tides of little movement), but shallow jetties are easier around high water. Autumn is calmest; summer south-east sea breezes build in the afternoon, so dive mornings. Port Giles is deeper than the other jetties so visibility often holds up a little better, but ship movements dictate diving more than weather: check that no vessel is loading or due before heading out.

From an anchored boat alongside the outer half of the jetty (well away from the berth), descend to the sand at 12-16 m, work the pylons along one side, then shallow up along the other. The old shore-dive advice still applies to route planning: the deepest and fishiest part is the outer end, so plan gas accordingly.

No regular operator since shore access was banned; occasionally dived by Adelaide club members and private boats out of Edithburgh when no ships are loading.