Whyalla began as a company town built around iron ore, and its original jetty, built in 1901 by BHP to ship ore from the Iron Knob mines to the smelters at Port Pirie, was the reason the settlement existed. The Marine Life Society describes the original jetty as disused for about 40 years with extensive growth on the pylons, in about 10 m. Decades without maintenance have allowed a dense community of sponges, ascidians, soft corals and algae to colonise the remaining iron and timber.

The Society lists tommy ruff, garfish, squid, blue swimmer crabs, Port Jackson sharks and whiting among the fish life, and the piles also host nudibranchs, crabs and small octopus. In winter, cuttlefish may be seen, as the upper gulf is their stronghold. The site is lightly documented and rarely dived, partly because the famous cuttlefish aggregation draws visiting divers away from town and partly because access is easiest by boat.

It is a good option for divers staying in Whyalla who want something different, particularly outside the cuttlefish season. Note that this is different from Whyalla's new foreshore jetty, opened in 2020 (see separate entry). Check current access with the local dive shop before diving, as it lies near industrial port areas.

Whyalla's steelworks harbour and ore-loading facilities remain active, so boat traffic, tugs and barges can pass nearby; fly a dive flag and keep a lookout on the boat. Outside the cuttlefish season the old jetty is one of the few structure dives close to town, and a torch brings out the colours of the sponges and ascidians in the shade of the piles.

Whyalla is about 390 km (4-4.5 hours) from Adelaide via Port Wakefield, Port Augusta and the Lincoln Highway, or a 45-minute flight. The old jetty site lies off the Whyalla foreshore south of the town centre near the steelworks harbour. Most divers approach by small boat from the Whyalla marina ramp (5-10 minutes).

Shore access may be possible from the adjacent foreshore, but check with Whyalla Dive Shop about current access and any industrial restrictions near the port.

Upper Spencer Gulf has no ocean swell; wind and tide control conditions. Strong southerly and south-westerly winds blow straight up the gulf and raise a short, steep chop, and northerlies stir the shallow water along the northern shores. Tides are large for South Australia (over 2 m on springs) and run hard around Point Lowly and in the shipping channels, so boat sites should be dived at slack water – visibility is often excellent (15-20 m+) at slack and murky when the tide runs.

Winter (May-August) brings the calmest mornings and cold water (11-13°C); summer water reaches the mid-20s but afternoon sea breezes are common.

Descend beside the piles, work along the line of the old jetty at 7-10 m inspecting the heavy growth, and return to the boat or entry point.

Whyalla Dive Shop (Why Dive) can advise and may guide; otherwise local and visiting divers with boats.