The Trial (Tryall) was an English East Indiaman of about 500 tons that struck an uncharted reef on 25 May 1622 — the first recorded English ship to encounter Australia and the oldest known shipwreck in Australian waters. Of her 143 crew, a minority escaped in boats to Java.

In 1969 John MacPherson and Eric Christiansen analysed the records, and diver Naoom Haimson found wreckage almost immediately on the south-western side of Tryal Rocks, including six cannon and up to eight period anchors. A large iron cannon is displayed in the WA Shipwreck Galleries in Fremantle. Although maritime archaeologist Jeremy Green judged the evidence equivocal, most researchers accept the identification. The Marine Life Network lists cannons, anchors and ballast stones at about 6 m, accessible only in calm weather.

The site is protected under Commonwealth legislation.

About the Montebellos: the group of more than 200 small limestone islands and islets lies 120 km west of Dampier and is protected as the Montebello Islands Marine Park, with more than 150 hard coral species, over 450 fish species, 170 echinoderms and 630 molluscs recorded. Flatback, green and hawksbill turtles nest here, and humpback, minke and Bryde's whales, dolphins and dugong frequent the waters. The islands carry a unique history: British atomic tests were conducted on and near Trimouille and Alpha islands in 1952 (Operation Hurricane) and 1956 (Operation Mosaic), and visitors are advised to visit rather than camp on those islands. Pearl farming has operated in the lagoons since the early 1900s.

The Montebellos lie about 120 km west of Dampier, 80 nautical miles from Onslow and 120 from Exmouth. There is no day-trip access for most divers: visits are by liveaboard or charter vessel (Montebello Island Safaris, based in Exmouth, runs multi-day charters and advertises dive liveaboards) or by private ocean-going boat, typically a 6–10 hour passage, anchoring in the islands' sheltered lagoons. Carry full safety and communications gear; there are no facilities.

Diving is best April–October outside cyclone season. The islands have a large tidal range (about 6 m at springs), driving strong currents through the channels; dive at slack water. Visibility is unpredictable — one operator suspended charters in 2022 partly because visibility often struggled to exceed 5 m — while the western outer reefs can be much clearer on calm days.

South-westerly and easterly winds limit which anchorages are usable.

Only in flat calm: anchor well off the reef, descend to the south-western side and view the cannons, anchors and ballast stones without touching.

Montebello Island Safaris (Exmouth) – multi-day charters and dive liveaboard trips; Image Dive suspended its Montebello dive charters in 2022. Otherwise private vessels only.