A 16-year-old boy from the east of England is hoping to become the youngest person to sail around the world - all by himself.
Michael Perham from Hertfordshire is already the youngest person ever to have sailed across the Atlantic alone.
He set sail on his latest record breaking attempt from Portsmouth on Saturday morning.
Before he left, Michael said he knows he's "a little crazy" to be attempting the journey.
Michael will be at sea for over four months, and the only contact he'll have with his family is over a special satellite phone.
He's expected to arrive back in Portsmouth some time around his 17th birthday, on 16 March 2009.
That means he'll be away for Christmas, so his family have put presents and decorations on board his yacht!
Michael's hoping to smash the current record held by Australian Jesse Martin, who completed his trip in 1999 when he was 18-years-old.
Michael said: "I'm a little bit nervous but otherwise really, really excited.
"It's just fantastic. But you don't look forward to the fact you are alone for about four months."