The Nikonos-V is an underwater film camera that many older SCUBA divers learned on, and some still do. Even though it is absolutely lovely, it is a pain in the ass to use compared to digital, and has largely disappeared. Nikon let the trademark go in 2008. Appears they just renewed it.
Another very interesting development: similar to the NOCT trademark, two weeks ago (on July 31st) Nikon also registered the "NIKONOS" trademark which was already expired back in 2008. This is what is listed under "goods and services":
"Cameras; optical apparatus and instruments; photographic apparatus and instruments; digital cameras; camera lenses; digital camera lenses; lens filters; rechargeable batteries for cameras and digital cameras; battery chargers for cameras and digital cameras; straps for cameras and digital cameras; caps for camera bodies; computer software; lens caps; camera cases; USB cables; audio video cables; LCD monitor covers; instruction manuals in electronic format; electronic publications."
A true purpose built digital underwater camera for divers, without a bullshit pain in the ass housing, from Nikon? Sounds like a dream. I use a GoPro now, but I used to dive with a Canon system, and before that a Nikonos V.