Montebello Islands (Conservation Park / Marine Park)

The Montebellos are a chain of around 174 islands roughly 100 kilometres off Karratha and Dampier, sitting on the edge of the North West Shelf. Britain detonated three atomic weapons here in 1952 and 1956 — Operation Hurricane on the HMS Plym, then Mosaic G1 and G2 — and the ground-zero sites on Trimouille and Alpha Islands still carry slightly elevated background radiation, with DBCA capping visits to one hour per day on each. The rest of the chain is one of the better reef and pelagic fisheries in WA, with over 450 recorded fish species and a Conservation and Marine Park managed by DBCA. There is no resort and no permanent population — this is a charter or private mothership trip.

Most trips are 5 to 10 day mothership charters from Dampier or Exmouth: a live-aboard parent vessel anchored inside the lagoon, with tenders running out each day to fish the reef edges and outer drop-offs. Troll skirted lures and bibbed minnows along the bommie lines for Spanish mackerel and tuna. Bottom-bounce on the deeper edges for red emperor, rankin cod and rosy jobfish; live-bait drift for coral trout and spangled emperor on the shallower coral. Cast stickbaits and poppers at the wash on the outer islands for giant trevally and queenfish. Run wider for sailfish and the occasional black marlin in summer. Lagoon mangrove pockets hold mangrove jack on a rising tide for the boat that wants something different.

Spanish mackerel, red emperor, spangled emperor, coral trout, rankin cod, GTs and queenfish are the staple mix, with samson, sailfish and the occasional mangrove jack from the lagoon edges.

Trimouille and Alpha Islands carry residual radiation at the test sites — limit landings to one hour and do not handle relics, dig soil or take souvenirs. The marine park has zoned sanctuary, special-purpose and recreation zones — get the current DBCA visitor map onto a plotter before you leave the mainland. Sharks are heavy on the deeper drops and tax slow-retrieved demersal fish; keep boat-side pressure on hooked fish or drop down on the next drift. The lagoons fish well at the change of tide when the bait stacks up against the coral edges.

Charter or private boat only. There is no town, no fuel, no ferry, no road. Mothership charters depart Dampier (around 16 hours from Perth, or fly into Karratha airport) and a smaller number depart Exmouth, on 5 to 10 day trips with all meals, bunks and tender fishing included. Private boats need to be a serious offshore platform with the range, fuel and self-sufficiency for a 100-kilometre crossing and several days at anchor — most private trips run as a small fleet for safety. There is some basic camping permitted in designated zones through DBCA permits but no facilities, no water and no waste collection. Leave with what you brought.

Tides run 3 to 4 metres on the springs and shape the lagoon and reef-edge fishing. Trade winds from the south to south-east blow hard most afternoons in the dry season — the morning window before 10am is the working time. Cyclone season runs November to April with serious storm potential and is the main reason most charters concentrate in the May–October dry. Water visibility is excellent in the dry and drops in the build-up. The crossing from Dampier kicks up fast in any south-westerly so weather windows are non-negotiable.

Residual radiation at the Trimouille and Alpha Island ground-zero sites — observe the DBCA one-hour limit, stay on hard surfaces, do not collect anything. Saltwater crocodiles are not common here but have been recorded in the broader Pilbara — treat the mangrove edges with the same caution as the mainland. Sharks are heavy and confident on the deeper drops. Cyclone risk November to April is the dominant trip-planning factor. The 100-kilometre crossing from Dampier is open ocean — EPIRB, working VHF, marine rescue log-on and a serviceable life raft are non-negotiable for private boats.

Mostly yes, with two clear exceptions. Trimouille and Alpha Islands still carry slightly elevated background radiation at the ground-zero sites and DBCA limits visits to one hour per day on each, with no soil disturbance and no removal of relics. The other 170-plus islands and the surrounding waters are at normal background levels and are fished and visited routinely. Charter operators brief these rules at the start of every trip.

Charter or private boat only. The most common access is a 5 to 10 day mothership charter departing Dampier, which is a 16-hour drive from Perth or a flight into Karratha airport. A smaller number of charters depart Exmouth. Private boats need to be a capable offshore platform with full self-sufficiency for the 100-kilometre crossing — most private trips travel as a small fleet.

Yes, in limited designated zones with a DBCA permit. There is no water, no fuel, no facilities and no waste collection — campers must be fully self-sufficient and pack everything out. The vast majority of fishing visitors stay on a chartered or private mothership rather than camping.

Over 450 recorded species. The reef and pelagic mix targeted by recreational and charter anglers includes Spanish mackerel, red and spangled emperor, coral trout, rankin cod, giant trevally, queenfish, samson, sailfish and mangrove jack along the lagoon edges. Sanctuary zones overlay parts of the chain — verify on the current DBCA visitor map before fishing.