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140,722-acre Gulf St Vincent. Sector 21 Australian saltwater fishing map showing only directly measured AusBathyTopo 2026 cells, source-qualified fishing spots, official regional fish evidence, seasonal forage context, access guidance and current-rule links. Sector 21 trip-scale surveyed footprint within Gulf St Vincent. The Adelaide gulf from its northern flats through central channels to Kangaroo Island-facing entrances. The displayed footprint is not a legal boundary or a claim of complete named-water coverage. The water tops out around 126 ft. The depth chart comes from Geoscience Australia / AusSeabed bathymetric survey data, so the contours are survey-derived rather than computer-modeled. Every species below gets its seasonal read from the same numbers driving the chart.
The outline encloses 140,722 acres, worked by 61.6 miles of shoreline. Nearly circular (index 1.2), so the story is the bottom, not the bank. Littoral water — the productive band under ~15 ft — makes up 6% of this chart. Tip to tip the water measures near 21.8 mi with a 17.7-mi widest point. Spencer Gulf - Sector 97 sits 7 mi north — the closest neighbouring chart.
Regional occurrence does not mean equal abundance, child-specific catch rate, retention permission or a promised catch. Live state, territory, Commonwealth, protected-area and local rules always control. The roster may combine exact-water monitoring with habitat-filtered official regional evidence; it does not imply that every species is equally abundant throughout the mapped section.
| Species | Evidence basis | Count / date |
|---|---|---|
| King George whiting (King George Whiting) | official species listing | — |
| sand flathead (Sand Flathead) | official species listing | — |
| black bream (Black Bream) | official species listing | — |
| Australian salmon (Australian Salmon) | official species listing | — |
| silver trevally (Silver Trevally) | official species listing | — |
| gummy shark (Gummy Shark) | official species listing | — |
| yellowtail kingfish (Yellowtail Kingfish) | official species listing | — |
| mulloway (Mulloway) | official species listing | — |
Official species-evidence source.
When the water first warms, king george whiting slide up into 3 to 18 ft. Summer is an 8 to 45 ft game here, winter an 11 to 45 ft one. Start at Shallow measured flat. It's a feeding flat holding about 4 ft of water and rates prime come spring. The feeding windows run early morning and the evening.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 18 ft | dawn & dusk | Shallow measured flat (4 ft) | see map |
| Summer | 8 to 45 ft | dawn & dusk | Sharp break (24 ft) | see map |
| Fall | 3 to 31 ft | dawn & dusk | Sharp break (24 ft) | see map |
| Winter | 11 to 45 ft | midday | Sharp break (24 ft) | see map |
Early season sand flathead use the shallows, holding in 8 to 35 ft. Expect a summer slide to 16 to 80 ft, then a winter hold in 8 to 35 ft. Put Sharp break first on the milk run — a drop-off near 24 ft that grades good for summer. In summer the feeding windows fall in early morning and the evening.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 8 to 35 ft | dawn & dusk | Shallow measured flat (4 ft) | see map |
| Summer | 16 to 80 ft | dawn & dusk | Sharp break (24 ft) | see map |
| Fall | 8 to 56 ft | dawn & dusk | Sharp break (24 ft) | see map |
| Winter | 8 to 35 ft | dawn | Shallow measured flat (4 ft) | see map |
Start shallow in spring: black bream sit in 2 to 16 ft that time of year. Summer pushes them deeper, 7 to 35 ft, and winter fish settle into 2 to 16 ft. The spot to know is Sharp break, a drop-off in about 24 ft of water that rates good for black bream in summer. Warm-month bites cluster around early morning and the evening.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 16 ft | dawn & dusk | Sharp break (5 ft) | see map |
| Summer | 7 to 35 ft | dawn & dusk | Sharp break (24 ft) | see map |
| Fall | 2 to 25 ft | dawn & dusk | Sharp break (24 ft) | see map |
| Winter | 2 to 16 ft | dawn | Sharp break (5 ft) | see map |
In spring, australian salmon run shallow here, mostly 4 to 30 ft. Midsummer fish sit out in 14 to 80 ft before dropping to 4 to 30 ft for winter. Summer australian salmon concentrate at Sharp break, a prime-rated drop-off around 24 ft. Fish it in early morning and the evening and you'll meet the bite.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 4 to 30 ft | dawn & dusk | Shoreline point (16 ft) | see map |
| Summer | 14 to 80 ft | dawn & dusk | Sharp break (24 ft) | see map |
| Fall | 4 to 56 ft | dawn & dusk | Sharp break (24 ft) | see map |
| Winter | 4 to 30 ft | dawn | Shoreline point (16 ft) | see map |
Start shallow in spring: silver trevally sit in 4 to 30 ft that time of year. Summer pushes them deeper, 14 to 80 ft, and winter fish settle into 18 to 80 ft. The spot to know is Sharp break, a drop-off in about 24 ft of water that rates prime for silver trevally in summer. Warm-month bites cluster around early morning and the evening.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 4 to 30 ft | dawn & dusk | Shoreline point (16 ft) | see map |
| Summer | 14 to 80 ft | dawn & dusk | Sharp break (24 ft) | see map |
| Fall | 4 to 56 ft | dawn & dusk | Sharp break (24 ft) | see map |
| Winter | 18 to 80 ft | midday | Sharp break (24 ft) | see map |
Start shallow in spring: gummy shark sit in 8 to 40 ft that time of year. Summer pushes them deeper, 18 to 120 ft, and winter fish settle into 8 to 40 ft. The spot to know is Sharp break, a drop-off in about 24 ft of water that rates prime for gummy shark in summer. Warm-month bites cluster around early morning and the evening.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 8 to 40 ft | dawn & dusk | Sharp break (24 ft) | see map |
| Summer | 18 to 120 ft | dawn & dusk | Sharp break (24 ft) | see map |
| Fall | 8 to 84 ft | dawn & dusk | Sharp break (24 ft) | see map |
| Winter | 8 to 40 ft | dawn | Sharp break (24 ft) | see map |
Gulf St Vincent - Sector 21 also holds yellowtail kingfish (19 to 126 ft in summer), mulloway (14 to 100 ft in summer). Pick any of them on the map above for rated spots and bait picks.
Structure-wise the chart holds 16 features, led in depth by Deepest basin at roughly 126 ft.
No facility from the cited South Australian boat ramps and marine facilities source was spatially attached within 3 km of this directly measured map footprint during the 2026-09-08 audit. This is an evidence gap, not a claim that public access is absent. Check the official portal, live site signs, tides, ramp condition, vessel suitability, fees, parking, working-port restrictions and landowner permissions before travel: https://www.sa.gov.au/topics/boating-and-marine/boat-ramps-and-marine-facilities
Private land and private launches need the owner's permission — please ask first.
Season dates, license requirements, and size and bag limits for South Australia waters are set by the PIRSA (current recreational species limits) — and special regulations can apply to Gulf St Vincent - Sector 21 specifically, so confirm the current rules before you fish. Check PIRSA's live species lookup, closures and SA Fishing app before every trip. Snapper remains absent from these page rosters because the current management closure prohibits targeting and catch-and-release in the affected South Australian waters through the stated closure period. Verify all size, boat and possession limits, protected areas, gear controls and local access directions. A contour, spot or access lead never grants fishing, retention, entry, parking or launching permission.
Check the official South Australia fishing regulations →
PIRSA SA Fishing app and live rules →
Check special-area and water-specific rules →
Gulf St Vincent - Sector 21 is about 126 ft (38 m) deep at its deepest point. The depth chart comes from Geoscience Australia / AusSeabed bathymetric survey data, so the contours are survey-derived rather than computer-modeled.
Official coastal monitoring from Primary Industries and Regions South Australia regional evidence informs the king george whiting, sand flathead, black bream, australian salmon, silver trevally, gummy shark, yellowtail kingfish, mulloway roster for Gulf St Vincent - Sector 21. The mixed roster combines exact-water records where available with habitat-filtered regional evidence; not every species is documented at this exact water, and it is not a promise of equal abundance or a catch on a particular trip.
Shallow measured flat is the top-rated area: a feeding flat in about 4 ft of water that rates prime for king george whiting in spring. Scroll up to the map for the complete spot list by species and season.
For king george whiting, the summer bite is best in early morning and the evening. Each species page section below lists the seasonal windows, and the map shows a live NOW badge when you're inside one.
Fishing on Gulf St Vincent - Sector 21 is regulated by the PIRSA (current recreational species limits). Check the official South Australia regulations for current license requirements, season dates, and size and bag limits — special regulations can apply to this specific water.
Spencer Gulf - Sector 97 7 mi · Spencer Gulf - Sector 105 15 mi · Gulf St Vincent - Sector 22 16 mi · Spencer Gulf - Sector 103 16 mi · Spencer Gulf - Sector 98 20 mi · Gulf St Vincent - Sector 26 21 mi · Spencer Gulf - Sector 102 26 mi · Spencer Gulf - Sector 90 30 mi · Gulf St Vincent - Sector 29 31 mi · Gulf St Vincent - Sector 19 31 mi · Gulf St Vincent - Sector 30 36 mi · Gulf St Vincent - Sector 14 37 mi
Browse all South Australia fishing maps. See every water on DepthScout. Bathymetry: published agency survey data. How we build these maps. Fish here with a sonar unit that logs? Send us your depth data and we'll improve this chart, credited to you. For fishing guidance only, never navigation.