Some of the world's best sailors will hit the waters of Cardiff Bay this weekend for the fifth stage of the Extreme Sailing Series.
The event is returning to the capital for the third year for its UK leg which will feature 40 catamarans. The race travels to some of the world's most iconic places including St Petersburg, Singapore and Sydney.
Olympic and America's Cup sailing star Sir Ben Ainslie is among competitors taking part in the event which runs until Monday. He skippers the British entry JP Morgan BAR.
It is crazy racing. Anyone who has seen the series, or taken part in it, will tell you that the style of the courses, the speed of the boats and the number of boats on any side of the course at one time means there is a lot of action and a lot of potential for crashes and incidents.
So it makes for exciting racing and you really have to be on your toes.
On our main programme and website all this coming week we'll have a series of reports about a tall ship that's sailing around the world visiting 30 countries on all 7 continents. The Crew is led by 21year old a injured soldier Kyle Baker from the Chepstow.
Cardiff's Olympic silver medallist has won her latest quest in sailing. Hannah Mills and her team crossed the line first in the Extreme Sailing Series Championship. The achievement comes just four months after London 2012. Our Correspondent Joanna Simpson reports.