Microsoft co-founder was ranked as the 21st richest person in the world

Paul Allen, the co-founder of Microsoft with Bill Gates, and the owner of a number of superyachts, has died aged 65 after battling non-Hodgkin’s lymphoma. He was ranked as the world’s 21st richest person by Forbes magazine with an estimated fortune in excess of $20bn.

His superyachts included the 126.2m (414ft) Octopus, one of the largest superyachts in the world. He also owned the 92.38m (303.3ft) Tatoosh and the 60.6m (199ft) Meduse. Octopus was built by Lurssen in 2003, the Tatoosh was completed by Nobiskrug in 2000, and the Meduse was a product of Feadship dating from 1996.

Allen used his yachts, particularly Octopus, to search for shipwrecks and other marine relics such as the bell of HMS Hood, once the pride of the Royal Navy in 2005. More recently his team found the Japanese battleship Musashi in 2015, the USS Indianapolis in 2017 and the USS Lexington this year.

Octopus was particularly well-equipped in her design for handling the research challenges Allen was interested in. The superyacht could land two helicopters, one aft and one forward, and she was equipped with a large garage and internal dock that could accommodate a 20m (66ft) submarine plus a similar-sized tender. Her interior designer was Jonathan Quinn Barnett.