And in any case, I'd still call the F/A-18 a successful carrier-based derivative of a land-based design.
I think that's kind of like calling a Chevrolet Monte Carlo NASCAR race car a "derivative" of the showroom model. The former is RWD, with a tube chassis, a V8 engine (with carburetor!), and a manual transmission. The later is FWD, with monocoque construction, a transverse V8 (fuel injected) and an automatic transmission. There is some visual resemblance, but that's about it.
wikipedia is certainly not a conclusive source, but it's the best I can find with limited effort. Full text is here:
http://en.wikipedia.org/wiki/F/A-18_Hornet
The Navy fought for and won permission to develop an aircraft based on the YF-17. Since the LWF did not share the design requirements of the VFAX, the Navy asked McDonnell Douglas and Northrop to design a new aircraft around the configuration and design principles of the YF-17. The new aircraft, designated the F-18, shared not a single essential dimension or primary structure with the YF-17.
The aircraft went from a gross weight of about 27,000 lbs to a gross weight of 37,000 lbs.