It's gold plated. Judging by the color of the picture, I'd say 14k or even 10gf, although the latter is pretty rare these days.
If it were 18k gold plate, then it'd look pretty nice, but the problem is that the finish will chip eventually. It's not a matter of if but when.
Congrats on the watch. It's worth more as a collector's item than for the gold content rest assured. I think your standard motherboard has more gold in it than the gold blade.
I've never heard of a watch made of pure gold (24karat). Leave that thing on a table and it would melt into itself because of it's own mass.