I've got a 6.75" wrist. Would a 46mm watch look too big? The world was what I had always wanted, but I thought that it'd wear too big, and the movement might break.
Everyone has opinions about watch sizes & I'm all about letting everyone wear whatever size they like.
You asked so I'll give my opinion for me. My wrist is 7 3/8" dia & as a general rule I like watches that are on the bigger side. I have had close to 100 watches now so I have a pretty good idea of what I like for me. As others have said not all watches with a certain dia wear the same. Some watches have long or short lugs or sometimes the od of the bezel will be bigger than the case or smaller than the case making the watch wear bigger or smaller than the case dia might imply.
With all that out of the way....
For a sport watch like a Navitimer my favorite size for me is a 42mm case with about a 43mm od of the bezel. If the od of the bezel is slightly larger than the case, it makes the bezel easier to grab so that is why I like it that way. I have had several Panerais that were 44, 45 & 47mm & the Blancpain Fifty Fathams @45 & have decided that 44 is my max. I really like Navitimers, but I won't order a Navitimer world as it is just too big for me.
So for me, I'm going to say in my opinion a 46mm dia watch is almost certainly going to look too big on you.