Contrary to general opinion, he thought it was the perfect material to have more aesthetic and design freedom, as well as reducing maintenance costs (almost to zero) and increasing production capacity. But it meant becoming familiar with a completely new material that was very different from wood, and for the workers at the Yard it wasn't an easy transition.
The first Riva-branded boat was built in 1969 and the 1970s began with the launch of fibreglass production across the entire range, in collaboration with the American yard Bertram, which had been using the material extensively for years and with excellent results. The first two Riva models in composite material were the Bahia Mar 20 day cruiser and the Sport Fisherman 25 cabin cruiser, followed by the Rudy. These models had exposed wood finishings, in keeping with tradition. In parallel, embittered by the adverse trade union climate, in September 1969 Carlo Riva sold the yard to the US firm Whittaker but remained as chairman and general manager until his resignation in 1971. These two posts were then held by his brother-in-law and business partner (since 1950) Gino Gervasoni. New and old models evolved and the Riva tradition lived on. Carlo Riva nevertheless continued frequenting the Yard for a further ten years as the tenant of "La Plancia", his old office.
In the 1970s, '80s and '90s various new models were launched. The highly successful Superamerica, a sporty flybridge produced in various lengths from 45 to 50 feet, was the first major cabin cruiser and remained on sale for over 20 years. Then came the Riva 2000, the St. Tropez - produced until 1992 - and the Corsaro 58, followed by the Black Corsair and the Riva 32 Ferrari. Despite the success of fibreglass, production of wooden runabouts continued until 1996, the year the last Aquarama Special (number 784) was built. In 1989, a year after the acquisition of 100% of Riva's stock by the UK group Vickers (which also included the Rolls-Royce brand), Gino Gervasoni, husband of Carlo Riva's sister, left the Yard after 41 years. This marked the end of the Riva family's involvement in it. At the 1991 Genoa Boat Show, Riva presented the 58' Bahamas, the first of its boats on which designer Mauro Micheli worked.