Thompson Beach and Port Parham Crabbing: Tides, Raking and the Rules

An hour north of Adelaide, past Dublin and a lot of wheat, the Adelaide Plains run out into Gulf St Vincent so gently that the sea seems to have lost interest. At low tide the flats at Thompson Beach and Port Parham stretch more than a kilometre out, still below the knee, and from October onwards they fill with people walking slowly backwards and staring at the sand. They’re raking blue swimmer crabs, and these two beaches are the best-known raking grounds in South Australia.

Raking is close to the only headline fishing still open in this part of the gulf. Southern calamari and southern garfish are closed to recreational fishers in Gulf St Vincent until further notice, and snapper is closed until 30 June 2027. Crabs are open on full limits all year. It’s October, the water is warming, and the season is starting.

When the Crabs Are On

Blue swimmers run on these flats from about October to April. The best of it is late summer into early autumn — February to April — when the water is at its warmest and the crabs are busiest. Spring builds as the crabs push into the shallows, and the October long weekend is when the foreshore car parks first fill. Midsummer brings the most crabs and the biggest crowds.

From about May to September the blue swimmers thin out and sand crabs take their place. Sand crabs are smaller and light brown, with two dark spots on the back. Winter isn’t a serious raking season on this coast.

None of that is a legal season. PIRSA lists no closed season for blue swimmer crabs, so the calendar follows water temperature, not regulations.

The Tide Decides the Day

Check the tide before you leave home. The method is simple: be on the flat at the bottom of the low, walk out, and rake your way back in front of the incoming tide. The bigger the low, the more sand drains and the more ground you can cover.

The trip to cancel is a dodge tide. For a day or two around the neaps, tidal movement in Gulf St Vincent almost stops, and the flat never drains. You’d spend an hour on Port Wakefield Road to look at a wet beach.

After the tide, wind is the next thing to check. A chop on the surface hides the dark sand patches that give the crabs away. Water clarity comes third. A warm, still, clear day has the crabs moving. An overcast, windless day on a big low is quietly excellent, because the glare drops off the water. The Thompson Beach forecast shows the tide range, wind and solunar times for the next seven days.

How to Rake

• Stay below knee depth and work the edges where clear sand meets the weed beds. That edge is where the crabs sit.
• Look for dark patches. A crab burying itself pushes darker sand up from underneath, and that smudge is the tell. Polarised sunglasses matter more than any other bit of kit, because you’re trying to see through a few inches of glare.
• Fish the channel edges. The tidal channels across the flat carry crabs into the shallows on the incoming tide and back out as it falls.
• Drag, wait, flip. Pull the rake across the patch, let the crab grab it, and flip the rake over while it’s still holding on.
• Measure every crab as it comes up, check under the flap for eggs, and put berried females straight back.

The local trick is a tub on a float or a set of wheels, towed on a rope from the waist. It looks ridiculous for about four minutes, until you watch someone carry a full tub half a kilometre back to shore.

The Two Flats

Thompson Beach

Thompson Beach sits about 56 km north of the city, reached through Dublin off Port Wakefield Road. The flats run one to three kilometres out, and reaching the far edge is a thirty-minute walk. Facilities are a foreshore car park and two public toilet blocks. There’s no jetty, boat ramp or kiosk. The water in front of the beach is a marine park habitat protection zone, where crabbing is allowed. A no-take sanctuary zone sits a few kilometres south toward the Light River and Port Gawler.

Port Parham

Port Parham is 7 km further north, about 63 km from Adelaide, on the same enormous flat. It has two car parks, two toilet blocks and a foreshore camping area. There’s no jetty and no boat ramp, so leave the trailer at home. The flat in front of the town is habitat protection zone, open to crabbing. A marine park restricted access zone — no entry at all — reaches the coast about a kilometre north-west of the foreshore. Check the Department for Environment and Water zoning map before you wander far in either direction.

Both flats are inside the Adelaide International Bird Sanctuary, a feeding, resting and nesting ground for shorebirds, including critically endangered species. Keep to the sand and follow any posted restrictions.

Further south at St Kilda, the St Kilda – Chapman Creek Aquatic Reserve has its own rules: blue swimmer crabs can only be taken by hand, crab rake or hoop net, and no other marine life may be collected. PIRSA’s reserve page has the map.

The Rules

Checked against PIRSA on 11 October 2026.

• Measure as you go. PIRSA requires every crab to be measured as soon as it’s caught, and undersize crabs go straight back. Fishwatch on 1800 065 522 will send you a free crab gauge.
• Boat limits only apply when three or more people are fishing from the boat. With one or two aboard, it’s the personal bag each.
• Bait in nets must be fish or fish-based. Meat, chicken and other poultry are illegal in hoop nets and drop nets in marine waters.
• Sand crabs have a 10 cm minimum and count toward the combined bag. Check PIRSA for their own limits in your zone.

Fisheries officers patrol these flats, and in May 2026 they fined a group of five at Thompson Beach $6,550. The group had 240 crabs, 221 of them undersize, and one of them had tried hiding his catch in seaweed. It’s a rare case of the seaweed being the most honest thing on the beach.

For every other SA species, see our SA size and bag limits guide and the SA closures calendar.

Gear

• Crab rake — PIRSA defines it as a hand-held pole and rake, with nets or mesh bags allowed. In marine waters you can use one rake alongside your other gear.
• Crab gauge — clip it to the tub, not the dashboard.
• Tub of seawater on a float or wheels.
• Hoop nets for deeper water: maximum 107 cm hoop and 92 cm bag depth. You can use up to 10 if no other gear is in use, or 3 if you also have a rod or handline out.
• Drop nets: same maximum dimensions, 3 per person.
• Shoes you won’t miss, and tough jeans or overalls for your shins.
• Polarised sunglasses, water and sun cover.

Safety on the Flats

The incoming tide is the real hazard. A flat that took half an hour to walk across fills in behind you, so work the incoming tide back toward shore rather than raking away from it, and turn around earlier than feels necessary.

Never go barefoot. Razorfish, rocks, spined fish, stingrays and blue-ringed octopus all live on this bottom, so shuffle rather than stride. Keep off the seagrass meadows, where the mud will take a shoe. There’s no shade and no water out there, and the walk back is the hard half. Carry drinking water for everyone in the group.

On eating the catch: the SA Government’s algal bloom health advice is that crabs you catch yourself are safe to eat if cleaned thoroughly and gutted before cooking. Self-collected bivalves — cockles, mussels, pipis, oysters, scallops — and abalone are still off the menu.

When the Flats Won’t Drain

If the tide is a dodge or the wind is up, stay in town. Crabs come up in drop nets off Largs Bay Jetty and Semaphore Jetty as the water warms, and the drive is a fraction of the distance. The Adelaide fishing report has what else is biting on the metro coast this month.

FAQ

When is the best time to rake crabs at Thompson Beach and Port Parham?

Blue swimmer crabs run on the Adelaide Plains flats from about October to April, with the best raking in late summer and early autumn, roughly February to April, when the water is warmest. On the day, be on the flat at the bottom of a big low tide and rake your way back to shore in front of the incoming tide.

What is the size and bag limit for blue swimmer crabs in SA?

PIRSA sets the minimum size at 11 cm across the carapace, measured from the base of the largest spines, and crabs must be measured as soon as they are caught. The daily bag is 20 per person and the daily boat limit is 60, combined with sand crabs. Females carrying eggs are totally protected and must go straight back.

Is there a closed season for blue swimmer crabs in SA?

No. PIRSA’s blue swimmer crab rules list no recreational closed season. The size limit, bag limit and protection of egg-carrying females apply all year in every South Australian fishing zone.

What is a dodge tide and why does it matter for crabbing?

A dodge tide is a day or two around the neaps when tidal movement in Gulf St Vincent almost stops. On the Adelaide Plains flats that means the sand never properly drains, so there is little or no ground to rake. Check the tide range before driving up and skip dodge tides.

Can I use chicken as bait in a crab net in SA?

No. In South Australian marine waters, hoop nets and drop nets can only be baited with fish or fish-based products. Any meat, chicken or other poultry is illegal in a crab net. Raking the flats needs no bait at all.

Is it safe to eat crabs from Gulf St Vincent during the algal bloom?

The SA Government’s algal bloom advice is that fish, crabs, prawns, lobsters and squid you catch yourself are safe to eat if cleaned thoroughly and gutted before cooking. Do not eat self-collected bivalves such as cockles, mussels, pipis, oysters or scallops, or abalone.

Before you load the rake, check the tide range on the Port Parham forecast, and read up on the crab itself on the blue swimmer crab species page.