The Carlisle Castle wreck marks one of the worst maritime disasters off Fremantle. The 1,344-ton, 70 m steel three-masted barque, launched in 1868, was bound from Glasgow to Fremantle with general cargo when a severe gale struck on the night of 11 June 1899. Unable to fix her position without sun or stars, she was driven onto Coventry Reef off Safety Bay and broke up. All 25 crew died, and only one body was recovered, near Warnbro Sound. The same storm wrecked the City of York at Rottnest.

The wreckage lies on a slope descending from about 6 m to 12 m. The eastern section is heavily overgrown with kelp, while the western parts are more exposed, with iron plates and frames forming little caves in the reef. Scattered among them are the remains of the cargo, including bottles, household items and building bricks. The site is protected under the Historic Shipwrecks Act, and nothing may be removed.

Fish life is good on the surrounding reef, with buffalo bream, wrasse, sweep, bullseyes and morwong, and crayfish in the gaps under the plates.

The reef is exposed, the approach crosses Five Fathom Bank and waves nearly always break over the site, so opportunities to dive it are limited to a few very calm days a year. Visibility on those days is often good, 10–15 m. It suits experienced boat divers with a sound understanding of swell and a well-equipped boat, and it rewards those interested in WA's shipwreck history. The WA Museum's shipwreck database holds further detail on the loss and the inquiry that followed.

Launch at Point Peron, Bent Street (Safety Bay) or Port Kennedy and head west-south-west past the Five Fathom Bank to Coventry Reef. The wreck lies at S 32°20.048' E 115°38.108'. Divingwawrecks marks a sand anchorage just north of the wreck; use it, and assess the swell carefully first, because moderate swell makes this a dangerous anchorage.

Allow 20–25 minutes each way.

Coventry Reef is exposed and waves nearly always break over it. The site is diveable only in very favourable weather, with swell under 1 m, light easterly winds and a reliable forecast, usually in the morning before the summer sea breeze. Any westerly swell turns the anchorage dangerous.

The approach crosses Five Fathom Bank, so plan the route in daylight.

Anchor in the sand patch north of the wreck, descend and follow the wreckage down the slope from the eastern (kelp-covered) section to the more exposed western section, looking for bottles and building materials among the plates. Return up the slope to the anchor, watching surge in the shallows.

No regular operator. Dived by clubs and private boats in very calm weather.