Name of a '60s technicolor movie (light comedy) about a family who decides to live underwater in a compound?

I remember seeing a movie in color that was about a family man/scientist who took his family to live with him in an underwater compound. It had some comedy such as a scene where the scientist's wife tells someone on the phone that she's moving to live underwater, and the person on the other end yells "UNDER WATER!!!???". 

I think the wife was blonde, I'm not sure though, but it was a light comedy with possible drama, but it was family-friendly. The movie might have been released in '60s. 

Does anyone know the name of this movie? Thank you very much.