Veteran sailor and yacht builder Max Tunbridge is currently testing a prototype of the catamaran-style craft.

He's calling it the Swordfish.

"Stand-up paddle boarding is one of the fastest developing sports in the world," Mr Tunbridge said.

His design was developed with boat designer John Sayer of Queensland.

And the prototype, constructed of polyester and foam, was made by surfboard maker John Gillies.

Two elite athletes are playing an integral role in its testing.

They are Mr Tunbridge's son, Cameron, who has represented Australia in K4 kayak racing, and Olympic windsurfer Lanee Beashel, of Balcolyn.

Ms Beashel also recently became the first woman on a stand-up paddle board to complete the 111km Hawkesbury Classic.

"The longer a board is, the faster it goes," Ms Beashel said.

"And with the two boards in the Swordfish it increases the stability, so the bottom of the craft can be shaped more dynamically."

Increased stability and speed are a winning combination, she said.

A similar craft has been designed in Hawaii, although Mr Tunbridge hopes that the unique features of his design will appeal to an international market.

"I think the Swordfish will appeal to the average person because of its stability as an exercise craft," Mr Tunbridge said.

"But it will also be very good for long distance down-wind racing."

If all goes to plan, the Swordfish could go into mass production locally early in 2012.