Cobia in WA: Where to Catch the Cobalt Opportunist

Cobia have a silhouette all of their own. A single low dorsal ridge of short spines, a broad flat head, a dark chocolate-to-cobalt back fading to a paler belly, and often a faint lateral stripe that’s bold on juveniles. At a glance they read as shark, remora or even a small cobia-shaped log drifting past — which is exactly the look that’s fooled every angler at least once.

The behaviour is the giveaway, and it’s the best thing about them. Cobia are opportunists that shadow big slow-moving animals — rays, sharks, turtles, even anchored boats — picking off whatever gets flushed out of the bottom. A stingray flapping across a sandy flat will frequently have a cobia or two tucked in behind it like an escort. Spot the ray, look for the shadow, and you’ve often found your fish before you’ve made a cast. They’re investigators rather than schoolers: usually solo or in pairs, slow to spook, and prone to swimming straight over to see what your lure is.

Be straight about range. Cobia are a northern fish in WA — Kalbarri is roughly the southern edge, and the fishing only really gets good once you’re into the Gascoyne and beyond. The best country runs from the Ningaloo coast up through the Pilbara and into the Kimberley.

• Exmouth — the obvious base. Cobia turn up on the Ningaloo bommies, around the Muiron Islands, and with grim reliability on the mooring buoys you pass on the run home. Always have a rod ready.
• Coral Bay — shallow inshore reef and ray traffic on the flats make this prime sight-casting country for fish you can actually see eat the lure.
• Onslow and the Mackerel Islands — isolated Pilbara structure, FADs and bommies hold cobia year-round, often mixed in while you’re chasing Spanish mackerel or trevally.

Cobia bite all year in the north, but they’re noticeably more active and more willing through the warmer months, roughly October to April. Tide changes and slack water around isolated structure are the prime windows. Bright, sunny days actually help here — flat light and a high sun make it far easier to pick a cruising fish off the shadow line of a bommie before it sees you.

Cobia sit inside WA’s statewide large pelagic finfish group, which carries a combined daily bag limit of 3 fish in total — and that three is shared across the whole category, so it’s any mix of cobia, mackerel, tuna, wahoo and barracuda, not three of each. The minimum legal size for cobia is 750mm. You also need a Recreational Fishing from Boat Licence (RFBL) to fish from a powered boat, which covers basically all cobia fishing.

Don’t take those numbers off a forum screenshot or this article a year from now — the statewide finfish limits were overhauled in 2026 and they shift. Read the current rules at DPIRD before every trip, and screenshot the page, because reception out on the Pilbara reefs is exactly as good as you’d expect.

There are three ways to put a cobia in the boat, and the situation usually picks the method for you.

Sight-cast. The most fun, and the one cobia are built for. When you mark a bommie or pass an anchored boat, give it a wide berth first and scan the shadow line. Spot a ray crossing a flat and watch its slipstream. Pitch a large soft plastic — a 7 to 9 inch jerkshad on a heavy jighead — ahead of a cruising fish and let it sink into its path. They’ll usually swim over to investigate and eat. Keep a pitch rod rigged and ready at all times; cobia appear and vanish in seconds and you don’t want to be re-tying while one cruises past.

Jig. Over deeper bommies, drop a slow-pitch or vertical jig and work it back through the structure zone. Cobia inhale lures, so a single heavy assist hook through the head holds best.

Bait. A live mullet or yakka, a whole pilchard or a fresh fish strip on a no-sinker or lightly-weighted rig, drifted past structure, is hard to beat when fish are around but not showing on top.

Whatever the method, gear up heavier than feels necessary: a heavy spin or overhead outfit, 30–50lb braid and a 60–80lb fluorocarbon leader, on a 7/0–9/0 circle hook for baits. On the strike, lock up and pull the fish away from structure immediately or you’ll lose it. Cobia are famous for one or two long, low, bulldogging runs before they sound — don’t relax until the leader’s in hand. Carry a wide-gape gaff rather than a net for anything over 15kg.

This is where cobia earns its keep. The flesh is firm, white, mild and unusually thick off the fillet — sashimi-grade when bled and iced the moment it’s boated, which up north means immediately, before the heat gets to it. Skin off, then pan-sear or grill the steaks; smaller fish crumb beautifully. It’s genuinely one of the best-eating pelagics on the WA coast, which is part of why a fish that fights this hard is worth keeping for the table rather than the photo.