Portsmouth, England — The world's youngest round-the-world sailor has returned to Britain after charting some 45,000 kilometres.

Thousands cheered as 17-year-old Mike Perham arrived Saturday in Portsmouth.

A Guinness World Records representative has certified Perham is the youngest person to sail around the world with assistance. He was 16 when he set off in November and turned 17 in March.

Perham tried to complete the challenge non-stop in his 15 metre racing yacht called Totallymoney.com, but technical problems forced him to be assisted.

Meanwhile, a Dutch court has ordered a 13-year-old girl who plans the same trip be given a psychological assessment to determine her ability to deal with two years of isolation.