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.
Barker said the differences around the design restrictions of the AC75 and the catamarans raced in Bermuda meant teams wouldn't know for certain how each other's vessels operated until they were racing.
"The catamarans produced great racing because they were relatively controlled in the design space; there wasn't huge areas to exploit, but Team New Zealand did a really good job with where they positioned themselves relative to everyone else in Bermuda.
"But in this particular edition, the first time with this type of boat and it's still a relatively open design space, there could be some pretty one-sided racing but it could be great, so it's too early to say until we see all the teams out there.
"For now we can just try to produce the best boat we can and make sure the next one is a step up again from where we are. It's certainly going to be a very interesting period through until we start racing in New Zealand."