The Mackerel Islands are a tight cluster of low, coral and limestone islands lying offshore from Onslow on Western Australia’s Pilbara coast. From the water they present an uncomplicated but remote-seeming archipelago: broad beaches, fringing reef and shallow lagoons punctuated by a few vegetated dunes and rocky points. Thevenard Island and Direction Island are the islands most commonly used by visitors and form a practical hub for visiting the rest of the group.
Sailing here is largely about sheltered island-hopping, reef fishing and short coastal passages rather than long exposed passages. The waters between the islands and the mainland are relatively sheltered from the full Indian Ocean fetch except in strong southerly or north-westerly winds; exposed outer reefs and shoals do, however, generate local swell and confused water close to the islands. The area suits trailer-boat anglers, family cruisers with local knowledge, and passagemakers who include the Pilbara coast in a longer north–south coastal itinerary. Visitors should be prepared for remote logistics: simple shore facilities on Thevenard and Direction islands, limited services elsewhere and operational rules for marine parks and fisheries.
Sailing the area
The Mackerel Islands sit as a compact chain of low, reef-fringed isles roughly 10–22 kilometres off Onslow on Western Australia’s Pilbara coast. From the water they read as a series of coral rims, sandy cayes and shallow lagoons: extensive fringing reef surrounds the larger landforms (Thevenard is the biggest and most developed) and creates a clear seam between exposed ocean and internally sheltered waters. That seam defines local cruising — short, often sheltered runs between reef-protected bays and beaches, punctuated by brief transits across exposed reef channels and the open Indian Ocean to the west. Sea state can change quickly when a passage crosses the outer reef, so local channel choice and timing matter for small cruisers and trailer-boats.
Sailing here is predominately day‑cruising, short coastal hops and reef exploration rather than long ocean legs. Most visiting yachts and trailerable craft operate from Onslow, which provides the practical base for fuel, transfers and embarkation; the islands are commonly visited by private boats, charter skippers and the island transfer services that run to Thevenard and Direction when operating. Vessels that suit the area are those with good manoeuvrability, shallow draft or reliable local knowledge — many stops are best reached by using protected reef channels on the lee side of islands when swell is present.
Geographically the group divides into exposed western rims facing open water and inner sheltered lagoons and bays to the east or inside the reef.
Best time to sail
The practical sailing window for the Mackerel Islands centres on the cooler, drier months roughly from April through October. During this period the sea state is generally calmer, visibility is usually best for reef-sightseeing and snorkelling, and the risk of tropical systems is low compared with the November–April “wet” season. Daytime temperatures moderate, daylight is long enough for comfortable cruising days and most charter and visitor services concentrate activity in these months. Between November and April the north-west Australian coast moves into the wet‑monsoon and cyclone season: heavier rain, short‑period gales and the occasional cyclone or ex‑tropical system make offshore work more exposed and insurance, operator availability and park access more changeable. Strong summer storms and increased turbidity also reduce snorkelling opportunities around reef and lagoon features. Shoulder months (March and October) suit experienced skippers who want quieter anchorages and wildlife windows such as seasonal fish movements, but must accept more variable conditions—late wet‑season groundswell or early spring wind changes. In all seasons local sea breezes, tidal currents and reef‑generated surge make timing and local knowledge important for comfortable daysailing and overnighting.
Main sailing areas
The Mackerel Islands cluster reads as a set of distinct sailing zones rather than a single uniform ground: low reef‑fringed cays and sandbanks, sheltered inner lagoons, narrow inter‑island channels, and the open shelf beyond where ocean swell and deeper fishing grounds take over. From Onslow the sequence you encounter—Beadon Creek and Onslow Bay, then the inner lagoon areas around Direction Island and nearby sand cays, the larger fringing reef and harbouring possibilities of Thevenard Island, secondary islets such as Brodie and Airlie, and finally the outer reef rims and shelf channels—defines sensible choices for day sails, weekend cruises and fishing trips. Each zone has its own sailing character and typical vessel use.
Sailors should think in terms of sheltered, semi‑protected and exposed areas. Sheltered waters are the shallow lagoon and lee sides of Direction and some smaller cays; semi‑protected places include the western and southern lee of Thevenard and the narrow channels between cays where tidal flow and wind interaction create short chop; exposed waters are the outer reef rims, the broad shelf east and west of the group and the approach sector from the open Pilbara shelf where swell, longer fetch and deeper water prevail.
Direction Island and its neighbouring sand cays form the most sheltered cluster for casual stops, snorkelling and short shore visits. The lagoonal water behind the reef has short fetch and calmer conditions in a favourable wind; small trailer yachts, tinnies and dinghies commonly work this area for afternoon runs and sheltered day anchoring. Narrow channels between cays can concentrate tidal flow at stronger springs, so timing matters for small‑boat manoeuvres.
Thevenard is the largest island and the practical hub for longer stays. Its fringing reef creates lee anchoring opportunities on the sheltered sides and provides quick access to nearby drop‑offs used by anglers. Expect more wind‑over‑swell on exposed reef edges; the island connects naturally to the sand flats and smaller islets to the north and east, making it a sensible staging point for multi‑day trips.
Anchorages and overnight stops
Thevenard Island and Direction Island are the established, visitor-facing overnight options in the Mackerel Islands and should be the first place to plan for when staying ashore. Thevenard provides a small fleet of visitor moorings for a range of boat sizes, daily fuel availability, a limited jetty and sheltered beach landings coordinated by the island operator; it is the principal hub for guest services, transfers and short-term berthing. Direction Island offers a more rustic overnight experience centred on the island’s single beach shack accommodation and sheltered sandflats; visiting yachts use the leeward shore or operator-managed landing arrangements for tenders. Both islands operate as a commercial tourism enterprise: berths, moorings, shore access and any transfers must be arranged in advance through the operator and you should expect arrival procedures and guest limits to apply. Check-in and radio communication protocols are used for private-boat arrivals.
Outside the two serviced islands there are several informal anchorages around smaller islets and lee bays that are popular for day visits, fishing and snorkelling. These spots typically offer shallow sandy patches with reasonable holding in settled conditions but only limited shelter when winds increase; skippers generally anchor to the lee of a reef or island and use a tender to get ashore. Public moorings away from Thevenard are limited or absent; some tourism or commercial vessels use private moorings. Onslow on the mainland functions as the gateway: the Beadon Creek maritime facility concentrates the boat ramp, visitor berthing, fuel and provisioning used by self-drive boats and yachts preparing to cross to the islands.
Arriving and getting around
Approaches to the Mackerel Islands are planned from Onslow: most private boats and commercial transfers stage from Beadon Creek and Onslow Beach Resort and cross 10–22 kilometres of continental‑shelf water to reach the islands. Thevenard and Direction islands each have buoyed channel approaches into mooring bays; private skippers are expected to pre-book moorings and check in with the island operator before arriving. There are no public deep‑water marinas offshore — landings are by mooring, sheltered beach, jetty or tender, and some small visitor moorings are limited by length and draft.
Once alongside, movement is normally by dinghy, charter launch or the operator’s tender. Fringing reefs and isolated bommies mean that inter‑island transits thread charted channels; rely on local marks, line‑of‑sight navigation and the marked pair of buoys into Direction’s bay. Tidal flows can strengthen through narrows and affect small‑boat handling during spring tides, particularly when paired with the prevailing trade winds.
Commercial fishing and occasional offshore support vessels operate around the islands; keep a proper lookout, monitor the island radio base and VHF (operator advises channel), and expect that crew changes, fuel and major spares are arranged via Onslow.
Facilities ashore
Onshore support for boat‑based visitors is concentrated in Onslow. The Onslow Beach Resort acts as the arrival and check‑in point for island visitors and provides secure mainland parking for cars, caravans and trailers plus coordination of transfers. The Beadon Creek maritime precinct is the principal launch and service hub: its dual‑lane public boat ramp has a floating pontoon, vehicle‑and‑trailer parking, a service wharf with marine fuel, a vessel wash‑down area and public toilets with a stainless steel fish‑cleaning station. Onslow also has a small supermarket, limited chandlery and hardware, and Marine Rescue Onslow based nearby for emergency response.
On Thevenard Island (the main visitor island) visitor facilities include a staffed radio base, licensed visitor moorings and daily fuel on request, plus bait, ice, freezer storage and a shaded fish‑cleaning area. Direction Island offers more limited facilities and accommodation. Practical limitations matter: there are no local boatyards or haul‑out facilities on the islands, so mechanical, rigging and major repairs must be arranged in Onslow, Exmouth or Geraldton.
Local hazards and limitations
The Mackerel Islands are defined by remoteness, reef and shallow fringing grounds; those physical features are the single biggest limitation for small-boat cruising. Many islands are low and coral- or limestone-fringed, with extensive reef flats that continue beyond the visible shoreline at lower tides. Nearshore seabeds include coral, rock and seagrass rather than uniform sand, so anchor holding can be variable and anchors are at greater risk of fouling on rubble or reef. Few fixed navigation aids mark reef edges and channels; visual navigation, an up‑to‑date chartplotter and a working depth sounder are essential in anything but settled conditions.
Ocean swell and wind‑sea wrap readily into the lee of reefs and narrow passes. The islands sit within broad Indian Ocean swell fields, so seas can become confused off windward sides and passes; local flows can strengthen through gaps between islands, producing set and brief, stronger currents. That combination makes stern‑to‑anchor situations uncomfortable at times and reduces shelter in exposures that otherwise look protected.
Operational limitations are primarily logistical. Visitor services, moorings and medical or salvage resources are concentrated on a small number of islands; most of the group has no facilities.
Regulations and responsible access
Mackerel Islands sit inside a patchwork of state-managed marine areas and federal conservation overlays, so be prepared for zone-specific restrictions on anchoring, mooring and take. Parts of the Dampier/Dampier Archipelago planning area carry sanctuary or special‑use designations where anchoring is limited or prohibited to protect reef and seagrass; licensed moorings (where provided) are managed under WA mooring and licensing rules and require approved hardware and compliance with licence conditions.
Port operations and commercial shipping around Dampier produce formal exclusion and transit zones; recreational craft should expect restricted areas, channel transit rules and vessel traffic procedures (including radio reporting) when approaching or crossing port limits. Cultural heritage controls affect many island shorelines — landing or beach camping can be subject to local restrictions or seasonal closures.
Practical obligations for visitors include observing WA speed and wash rules, using licensed moorings where available, complying with marine park zone rules and Western Australian recreational‑fishing limits, and avoiding anchoring on reef or seagrass.
Suggested sailing experiences
Island‑hopping snorkel and beach day
Short hops between Thevenard, Direction and nearby islets make a classic sheltered‑water day for trailer boats, walk‑arounds and small cruisers. Stay inside the reef edges, use marked channels and pick leeward beaches for swimming and snorkelling on fringing reef. This is a relaxed social day—shore picnics, reef swims and short snorkel drifts—where changing wind and tide can quickly alter which beach is sheltered.
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Sportfishing runs to reef passes
Half‑day or full‑day fishing trips target Spanish mackerel, coral trout and pelagics on outer reef edges and reef passes. These outings often use fast centre‑consoles or small catamarans capable of brief exposed runs of 10–22 km from Onslow. Choose weather‑sturdy boats and experienced skippers for open legs and prepare for short, choppy sea states on exposed sections.
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Weekend cruise with island stays
Use Thevenard or Direction Island accommodation as a base for a weekend circuit: tie up to a mooring or land at designated jetties, then day‑trip between nearby reefs and bays. Suits couples and families wanting shore comfort with short overnight hops; reduces the need for full self‑sufficiency but requires careful planning for arrivals and departures on variable winds.
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Passage staging and coastal linklegs
For passagemakers running the Pilbara coast, treat the Mackerel group as a tactical stop for crew relief, reef workups and short shelter before long coastal legs north to Dampier or south towards Exmouth.
Who this destination suits
The Mackerel Islands best suit short‑haul coastal cruisers, anglers and small‑boat snorkellers who want reef fishing and island camping without committing to long offshore passages. They work well for trailer‑launched tinnies, walk‑around weekender cruisers and shallow‑draft cruising yachts that can moor off Thevenard or make day hops to Direction Island; powerboats and game boats are particularly common because of the fishing focus and available moorings and fuel at Thevenard. Crews should be comfortable navigating reefy approaches, managing tidal runs near headlands and organising provisioning and transfers from Onslow.
These islands are less suitable for large keel‑yachts seeking full marina services, for sailors who prefer sustained sheltered waters, or for novices unable to handle exposed lead‑ins or basic off‑grid anchoring and communications.
Sources consulted: en.wikipedia.org, exploreparks.dbca.wa.gov.au, mackerelislands.com.au, dbca.wa.gov.au, dpird.wa.gov.au, epa.wa.gov.au, fish.wa.gov.au, pdc.wa.gov.au, visitashburton.au, westernaustralia.com