They may be some of the world's best sailors with more than a hundred world titles between them. But even athletes like four-time Olympic champion Ben Ainslie finds negotiating the Marina Bay waters tricky.

The Extreme Sailing Series begins on Thursday at The Promontory, featuring 12 teams sailing on speedy Extreme 40 catamarans. Singapore is kicking off the first of the eight-stop circuit.

Said Briton Leigh McMillan, who won the series last year with The Wave, Muscat: "It was very challenging last year and it's always going to be on a (tight) course like this. The wind can do crazy things around these buildings and it becomes more difficult to predict.

"It comes down to being consistent and trying to keep it cool in this very hot environment. It's going to be a lot of fun."

Oman Air's Rob Greenhalgh got a taste of how tricky the sailing can be firsthand, when his side crashed during practice on Wednesday.

Said the Briton: "It's a tiny race area and for sure there's going to be plenty of bumps and scrapes. These things happen, it's part of the game."

This year's line-up of teams is one of the strongest yet, with America's Cup runners-up Team Emirates New Zealand also fielding a side, setting up a potential rematch between skipper Dean Barker and Ainslie, who masterminded Oracle's America's Cup win. Frenchman Franck Cammas, a Volvo Ocean race champion, is also competing.

Singapore sailors will be part of Team Aberdeen Singapore, with Scott Glen Sydney and Justin Wong competing in the local entry team. The side is skippered by offshore legend Nick Moloney of Australia.

Races end on Sunday. Members of the public can watch the races for free at The Promontory's race village, which will be open from 11am from Friday onwards.