Three Scottish brothers have embarked on a mammoth journey from Peru hoping to set a record time for rowing across the Pacific Ocean.

Ewan, Jamie and Lachlan MacLean set off in a carbon fiber dinghy from Lima, aiming to reach Sydney in Australia 9,000 miles (14,500 kilometres) away in about four months.

The trio from Edinburgh, who previously rowed across the Atlantic Ocean, are hoping to raise more than $1 million for clean water projects in Madagascar in the process.

"We're going to be rowing non-stop with no outside support, so we'll be on our own," Lachlan MacLean told AFP before boarding.

They departed shortly after 4:00 pm (2100 GMT) on Saturday after a brief ceremony during which youngest brother Jamie played the bagpipes accompanied by the Peruvian Navy band.

"One of the real challenges is the sleep deprivation. You're rowing through the day and through the night continuously and shifts," eldest brother Ewan said. "It's absolutely relentless."

The brothers plan to sleep five to six hours every 24 hours and row 12 to 14 hours a day for 120 to 150 days.

"This project is all to raise money for clean water projects in Madagascar" through their charity, the MacLean Foundation, Lachlan said.

"Clean water is the most basic human need on the planet but 10 percent of people worldwide don't have access to it," they said on their website.

Only 14 percent of Madagascar's rural population has access to a clean water source, they said.

"Ocean conservation and keeping our oceans clean, it's all part of the same parcel," Lachlan said.

The brothers broke three world records crossing the Atlantic Ocean in 2020, without ever having rowed professionally, raising more than $260,000 for charity.

(AFP)

Scottish rowing brothers aim for record-breaking Pacific crossing