Two of the UK’s best veteran yachtsmen are to circumnavigate again. In separate challenges, Sir Robin Knox-Johnston and Tony Bullimore, both aged 67, will be pitting experience against youth in two of the toughest round-the-world challenges.

Knox-Johnston, the first man to sail single-handed, non-stop around the world in 1969, is to compete in the Open 60 class of the Velux 5 Oceans race, which starts in Bilbao in October. Voted Britain’s most successful solo yachtsman by The Sunday Times, Knox-Johnston was the only person to finish the Golden Globe on board his yacht Suhaili. The circumnavigation took a mammoth 313 days, during which time the paper prepared his obituary, believing him to have been lost at sea.

Tony Bullimore, meanwhile, takes on Ellen MacArthur as an adversary, when he sets out to break the 70-day barrier for a single-handed non-stop circumnavigation. It will be his first solo world record attempt since his disastrous participation in the 1997 Vendée Globe, where he capsized in the Southern Ocean, spending five days in his upturned hull before being rescued.

The former nightclub owner hopes to beat Dame Ellen’s record of 71 days, 14 hours and 18 minutes, in his 102ft catamaran, which will be named later this month.