MichaelC[AP Moderator]
22345
Hello Friend...
I recently to town and caught your reply to this older post.
Yes, the RB2 strap is leather with an alcantara lining on the inside. You are also correct about the Grand Prix straps not being compatible with the 42mm Royal Oak Offshore collections.
Knowing now that you have the Navy, you might consider ordering one or more of the straps supplied with the new 42mm Offshores. The blue dial in particular is supplied with a dark blue rubber strap that would pair great with your Navy, especially during hotter seasons and sports activities. I was told they will make a dark blue croco strap for that watch as well. You could probably order it with white stitching which would be amazing on the Navy. The nice thing about the new straps is that they are made for a pin buckle, and many owners find more comfort with that arrangement than they do with a clasp model.
As far as a direct alcantara strap, there is not really a Grand Prix style strap to fit the 42mm Offshores at this time.