People are being encouraged to come to Portsmouth to cheer on the home team – Ben Ainslie Racing.
The America’s Cup is the competition for the oldest trophy in international sport and dates back to 1851.
It is taking place over the next four days in Southsea.
Event director Leslie Greenhalgh said: ‘It is the start of a big four days.
‘We have put so much into making it a success.
‘We have our fingers crossed for the weather as it’s a big part of sailing.
It is a once-in-a-lifetime opportunityEvent director Leslie Greenhalgh
‘But we are very excited.’
The Louis Vuitton America’s Cup World Series is a racing circuit featuring the best sailors in the world, competing on foiling, wingsailed catamarans.
The Portsmouth event is one of the qualifying stages where teams bid for points ahead of the 2017 America’s Cup final in Bermuda. It began in 2015 with three events and continues in 2016 with six scheduled regattas.
The opening event took place in Portsmouth last year and saw nearly 250,000 spectators cheer on local hero Sir Ben Ainslie as he led his Land Rover BAR crew to a crowd pleasing victory.
Ms Greenhalgh encouraged people to come along and show their support once again.
She said: ‘People should come and show their support.
‘People in Portsmouth have such a fantastic facility here. It is a once-in-a-lifetime opportunity.’
Racing officially takes place on Saturday and Sunday, although a wide range of practice events are taking place across today and tomorrow.
Go to lvacwsportsmouth.com/ for more information.