AeroHydro (Popularity: )
http://www.aerohydro.com/ Marine design with Relational Geometry, collection of other tools such as a VPP, Hydrostatics and Plate expansion applications.
Autoship (Popularity: )
http://www.autoship.com/ Ship design software for the largest projects - from general design to building.
Hydrocomp Inc. (Popularity: )
http://www.hydrocompinc.com Design marine software products including performance prediction, propeller selection, and propeller CAD modeling software.