Spencer Gulf is the larger and wilder of South Australia's two gulfs, 180 miles from its mouth to Port Augusta at its head. Port Lincoln, near the mouth on the western shore, sits on Boston Bay, one of the largest natural harbours in the world and the centre of the tuna and aquaculture industries; the Sir Joseph Banks Group and Thistle Island offshore are remote anchorages; the eastern shore is the Yorke Peninsula's rugged foot at Innes; and the head of the gulf around Whyalla and Port Augusta has strong streams and industrial shipping. The Adelaide to Port Lincoln race each January is the state's classic passage, 150 miles through Investigator Strait and across the gulf mouth with Southern Ocean swell coming in from the west.
The waters
Boston Bay and Port Lincoln
A vast sheltered harbour with a marina, a commercial port and tuna farms; Boston Island shelters it from the east. Anchorages around the bay.
The Sir Joseph Banks Group and Thistle Island
Islands 20 to 30 miles from Port Lincoln with sandy anchorages, seals and sharks; settled-weather destinations.
The gulf head: Whyalla and Port Augusta
Shallow, tidal, industrial water with streams of 2 to 3 knots; Port Augusta at the very top is a long way from the sea.
Investigator Strait and the gulf mouth
The open water between Kangaroo Island and the Yorke Peninsula; swell from the west and the passage between the gulfs.
Training here
Port Lincoln supports sheltered training in Boston Bay with remote-island passages and open-gulf sailing beyond. Distances are long and shelter is sparse, which teaches conservative passage planning.
What an exam here looks like
Passages for the logbook
| Passage | Miles | Notes |
|---|---|---|
| Port Lincoln to the Sir Joseph Banks Group | 25 | A day sail to a remote anchorage. |
| Port Lincoln to Adelaide | 150 | Overnight across the gulf mouth and through Investigator Strait; qualifying passage. |
| Port Lincoln to Whyalla | 120 | Up the gulf; long, exposed and tidal. |
| Port Lincoln to Streaky Bay | 150 | Round Cape Catastrophe into the Bight; expedition sailing. |
Conditions
| Tides | Mixed, range 2 to 3 m; the dodge tide at neaps. Streams of 2 to 3 knots at the gulf head and around the islands. |
|---|---|
| Weather | Sea breezes and hot northerlies in summer; westerly fronts in winter; heavy Southern Ocean swell at the gulf mouth and along the west coast of the peninsula. |
| Facilities and rescue | Port Lincoln Marina, the Port Lincoln Yacht Club, Whyalla Marina; Sea Rescue at Port Lincoln and Whyalla. |
Boat licence
Questions about Port Lincoln and Spencer Gulf
Are the sharks a real consideration?
Great white sharks are present around the offshore islands and the tuna farms. It changes nothing about seamanship except that nobody enters the water voluntarily; man-overboard recovery is line and ladder only.