Hey Saltlife. A surface iron is a larger sized lure that is made of aluminum. Typically they are cast toward breaking fish or working birds and retrieved at a moderate speed just under the surface. The technique has evolved lately but is still mostly done with rods between 8 and 10 feet, lighter weight reels, and 40lb line. There is, and has been, endless debate on sizes, brands, and colors of the irons. It's my absolute favorite way to fish. Pick your target, make a long cast, start your retieve, and watch nice fish blow up on your jig. Serious adrenalin.
http://www.youtube.com/watch?v=Nk2KmcBarTU
These will give you and idea. Mike