After one month at sea Australian sailor Jessica Watson is almost at the equator.

The 16-year-old from Queensland is trying to become the youngest person to sail around the world solo on board her 10-metre yacht Ella's Pink Lady.

Jessica's 38,000 kilometre voyage began a month ago, from Sydney. She must cross the equator at least once and plans to sail southeast towards Cape Horn in South America.

In her blog, Jessica describes progress as being "a little on and off over the last few days. When we have a little wind, Ella's Pink Lady flies along the flat water amazingly. But there's also been a few times with not any wind. This afternoon particularly was a little un-exciting, just rolling around not going anywhere in the heat."