Dean Barker has raised concerns over how competitive the America's Cup will be, due to the 'relatively open' design space of the AC75.
Barker, who will skipper the New York Yacht Club's American Magic challenge, has competed in several editions of the regatta since 2003 and told Radio Sport there was a lot to learn before the 2021 edition.
"There's no question these boats are going to be pretty spectacular once they're fully up and running," Barker said.
"The thing no one can really answer is if the racing will actually be very close because there's the opportunity that one team steals the march from everyone else, then the racing could end up being very one-sided."
Team New Zealand and American Magic were the first to unveil their first full-scale AC75s, with the American crew already foiling on their 75-foot monohull.