Three years after the old proposal to build a surf park at Alfred Cove collapsed, a new proponent has signed a 21-year lease with the state government for an alternative $100m project in Jandakot that contains all the bells and whistles.

Touted as the biggest surf park in the southern hemisphere, with 150m-long waves, it will be built with special government assistance to guide it quickly through red tape.

Aventuur chairman Andrew Ross, who was part of the old proposal that was rejected, told Gareth Parker on 6PR Breakfast the new site wasn't available the first time he began exploring options for a wave park in Perth.

"This site is really interesting.. it's probably better than the Tompkins Park site, there's transport connectivity (next to Cockburn), the site is bigger and it allows us to place the lagoon in the perfect position into the prevailing winds, meaning we've got offshore conditions for most of the year," he said.