I apologize in advance for what will be a long-ish answer to a simple question.
A little over a year ago I was just developing an interest in mechanical watches but I didn't understand what the fuss was about regarding the Speedmaster Moonwatch. About one year ago today I was standing in line to board a flight from NYC to LA and I happened to notice that the guy behind me in line was wearing a Speedmaster with exactly the same setup you see in my photo today. It was really eye-catching and I complimented the guy on his watch, and right then and there I realized it was a watch I wanted to wear someday, with exactly that strap.
The strap is a dark brown calfskin Omega strap, with a brushed stainless steel Omega deployant buckle. The strap came with a 15'000 gauss Aqua Terra that I had purchased recently, knowing exactly what I was going to do with it when I bought the Aqua Terra: put its strap on a new Moonwatch. I had a spare Aqua Terra stainless steel bracelet sitting in a drawer that I put on the Aqua Terra 15'000 gauss. When I bought the Moonwatch I got it with a black alligator strap so that I could put
that strap on my Apollo-Soyuz (meteorite) Speedmaster (which looks fantastic with its polished deployant buckle). And that's how I got the look I wanted for my Moonwatch from the day I saw it in the airport.
It was a lot of fun planning and executing my grand strap swap scheme, nearly as much fun as wearing the watches themselves
😀