Where are the Mackerel Islands?

The Mackerel Islands are a cluster of low coral islands roughly 22km off Onslow in WA's Pilbara, north of Exmouth and Ningaloo Reef. Thevenard Island is the main one, with self-contained beachfront cabins, and access is by private boat across from Onslow (about 45 minutes) or by light plane from Exmouth.

What can you catch at the Mackerel Islands?

Spanish mackerel are the namesake, alongside giant and golden trevally, queenfish, cobia, tuna, wahoo and sailfish on the pelagic side. The reefs hold demersals — red emperor, coral trout, rankin cod, spangled emperor and bluebone — making it a genuine mixed-bag destination.

Do you need a boat to fish the Mackerel Islands?

Yes, in some form. You either bring your own boat across from Onslow, book a charter that departs from Onslow or Thevenard Island, or fly in by light plane and fish from the resort's charter vessel. There is no public ferry running in 2026, so a boat — yours or a charter's — is essential.

When is the best time to fish the Mackerel Islands?

The accommodation season runs roughly April to October, sitting either side of the worst cyclone risk. Spanish mackerel and pelagics fish through the cooler, calmer months, while sailfish peak in spring and early summer. Settled weather is the real limiter this far north — the fishing follows the wind window.

What are the bag and size limits at the Mackerel Islands?

The islands sit in the North Coast Bioregion, which has its own demersal and pelagic limits — different from the West Coast rules most Perth anglers know, and there is no West Coast demersal closure up here. Limits change, so check the current rules at DPIRD before you go rather than relying on what applied last trip.

Fishing the Mackerel Islands off Onslow: A Destination Guide

Some places are named after the fish for marketing reasons, and some because the fish are genuinely the point. The Mackerel Islands are the second kind. This low scatter of coral islands sits about 22km off Onslow in the Pilbara, north of Exmouth and Ningaloo, and the Spanish mackerel that gave them their name still show up on cue when the water settles. It’s a holiday-and-fishing destination as much as a spot — beachfront cabins, blue water, and reef that holds far more than just the namesake.

This is the honest version: what’s out there, how you get to it, and what the trip actually involves.

Getting There and the Setup

There’s no road to the Mackerel Islands and no public ferry running in 2026. You get there one of three ways: your own boat across from Onslow — roughly a 45-minute run over 22km of open water — a charter from Onslow or the island, or a light plane into Thevenard from Exmouth (about 35 minutes) or Onslow (around 10). The own-boat option is the cheapest and the most committing; this is exposed Pilbara water, and the crossing demands a seaworthy boat and a real weather window.

Thevenard Island is the hub. It carries a row of self-contained, air-conditioned beachfront cabins, which is what turns this from a day mission into a proper destination — you fish hard, then sleep 50 metres from where the boat’s moored. Direction Island, the other half of the operation, is closed for the 2025/26 season, so plan around Thevenard. The accommodation season runs roughly April to October, deliberately sitting either side of the worst of the cyclone window.

What’s Biting and When

The headline is pelagic. Spanish mackerel hold on the current lines and bommies and crash a trolled bait with the kind of reel-scream that ruins you for jetty fishing. Around and under them you’ll find giant trevally and golden trevally working the shallow reef, queenfish busting bait on the flats and creek mouths, cobia cruising isolated structure, plus tuna and wahoo through the warmer water. The shelf isn’t far off, so the gamefishing extends to sailfish and the odd marlin for boats willing to push out and troll the blue.

Drop a rig to the bottom and a different fishery opens up. The reefs hold serious demersals — red emperor, coral trout, rankin cod, spangled emperor and bluebone all come up on the same drifts. That mix is the real draw: a single day can run from trolling for Spaniards in the morning to bottom-bouncing reds over rubble in the afternoon. Timing is governed less by a calendar than by the wind — the cooler months from autumn through spring give the most settled water, and sailfish lean toward spring and early summer. Up here the fishing follows the weather window, not the other way around.

The Marquee Species

The Spanish mackerel is the fish on the sign, and it earns it. They run to 20kg-plus, hit a trolled lure or rigged bait at speed, and the first run off an overhead reel is the reason people book the trip in the first place. They sit on the productive bommies and pressure edges year after year, so the local knowledge a charter brings is worth real money.

For sheer violence, the giant trevally is the other marquee fish. GTs patrol reef sometimes skinny enough to see their backs out of the water, and the strike on a surface popper is among the most brutal in fishing. They fight dirty, run straight for coral, and test every knot and split ring you own. Most are tagged and released — eating quality drops off in big fish, and there’s a ciguatera risk in tropical reef predators — so this is a sport fishery, not a feed.

Gear and Technique

Match the tackle to the job and bring two setups. For the pelagics, a 15kg overhead or heavy spin outfit, 50–80lb braid, and a single-strand or heavy mono bite trace — mackerel teeth go through ordinary leader like cotton. Troll hard-bodied minnows, skirted lures or rigged garfish at 6–8 knots along current lines and reef edges. For trevally and queenfish, a stickbait-and-popper spin outfit with 40–50lb braid lets you sight-cast schools busting bait at change of light.

For the demersals, switch to a paternoster rig with 8/0–10/0 circle hooks on heavy droppers, an 80–100lb leader, and enough lead — often 16oz and up — to hold bottom in current. Reds and bluebone bury into structure on the strike, so it’s a fast, hard lift. Big baits keep the pickers off: whole squid, flesh strips and pilchard. A descender or release weight is standard kit up here — demersals suffer barotrauma from depth, and a surfaced fish is a wasted one.

Practical: Charters, Own Boat, Accommodation

The simplest way in is a charter package out of the resort — a centre-console running up to six anglers, gear and bait supplied, with a skipper who already knows the marks. Packages bundle cabin accommodation with the boat days, which suits a group splitting the cost. Bringing your own boat is cheaper per head and gives you freedom, but it puts the crossing, the reef knowledge and the safety margin on you — log a trip plan, carry the right gear, and don’t push a marginal forecast across 22km of Pilbara water. Either way, book ahead: cabins on Thevenard are limited and the good-weather months fill.

Rules: Check Before You Go

The Mackerel Islands sit in the North Coast Bioregion, and the rules here are not the rules most Perth anglers carry in their heads. There’s no West Coast demersal closure up north, the demersal mixed-bag arrangement differs, and pelagic limits — including for Spanish mackerel — have their own settings that have been adjusted in recent reforms. Don’t take numbers off a charter mate, an old guidebook, or this article. Read the current bag, size and possession limits at DPIRD before the trip, and screenshot them — mobile reception out on the islands is patchy at best. Demersals like red emperor and bluebone are slow-growing and tightly managed for good reason; fish to the current numbers, weight your releases back to depth, and the fishery stays worth the airfare.

The Mackerel Islands are one of WA’s genuine fishing destinations — Spanish mackerel on the troll, GTs in the shallows, and trophy reds on the bottom, all from a cabin on a coral island off Onslow. Plan the weather window, sort your boat or charter, and check the current rules at DPIRD. Then watch the Spanish mackerel forecast and pick your run.