How do you spend $13 billion in Microsoft co-founder Paul Allen style?
The other super yacht of Microsoft co-founder Paul Allen, the OctopusReuters

A yacht owned by Microsoft co-founder Paul Allen had a disastrous run-in with a protected Cayman Islands coral reef and destroyed close to 80% of it, say local environmental officials.

The 300ft (91m) yacht, Tatoosh, reportedly seriously damaged the reef in early January although Allen was apparently not on board at the time.

The Tatoosh had been moored near two dive sites on the western coast of Grand Cayman, north of the capital of George Town when the damage occurred.

Following an inspection by local divers to assess the impact, officials determined that Tatoosh wrecked an estimated quarter of an acre (1012sq m) of underwater terrain. Inspectors believe the damage was caused by one of the yacht's chains when it was anchored.

Coral reefs are vital for marine life to flourish and help protect coastlines from big waves and tropical storms.

Allen's company Vulcan issued a statement saying that the yacht was "moored in a position explicitly directed by the local Port Authority." The crew moved the vessel as soon as they were notified of potential damage. "Vulcan and Paul G. Allen have a long history of responsible exploration and a commitment to ocean conservation," statement added.

"Shifting winds reportedly changed the position, pushing the ship toward the reserve but it was relocated to avoid damage," the Cayman News Service reported.

The yacht's crew and Allen are fully cooperating with authorities, said a Vulcan spokesman. Maximum fines for the damage could run to $600,000 (£421,000).

In addition to investigating Tatoosh's role in the damage, officials are "also paying close attention to lessons learned so that we can more effectively prevent these accidents while still hosting visiting yachts," said a spokesperson for the Cayman Islands Department of the Environment.

Allen, 63, is worth about $18bn (£13bn). He owns the Seattle Seahawks football team and the Portland Trail Blazers basketball team.

Tattoosh, the 49th biggest yacht in the world, has a crew of 30 and two helipads. It has been described as a "model of understated luxury." Allen also owns a second super yacht, the Octopus, which is 414ft (126m) long.

Allen prides himself on being a friend of the environment and is known for his ocean charity and seafaring adventures.

Among his many conservation projects is the Paul G. Allen Ocean Challenge, which funds research that could help mitigate environmental effects from ocean acidification. In 2012, Allen financed an expedition to try to recover the bell of the Royal Navy battle cruiser HMS Hood, which was sunk by the Nazis off Denmark in the Second World War. In 2015 another Allen expedition located Japan's warship Musashi, also lost in World War II.