Was considering 5167 Aquanaut and found out that the 5065 firs my 6.75"/17cm wrist perfectly. Was always intrigued by 3800 Nautilus (never had a chance to try it on) and worried that it would be on a smaller side....but judging from your pics, I think it would fit just fine.
Also noticed that you own 5065. How does the 3800 feel on your wrist vs 5065 ? (larger, smaller, about the same?) Thank you.