It's hard to say for sure because the material and shape of the bracelet are different, but the 3800 fits better. However, the 5065 bracelet model is more roomy and comfortable to wear.
The 3800 blue dial was available in several colors, from light to dark (according to a collected man), and the dark navy one was said to have the French word βnoir" written on the warranty. Is my dial medium blue? Photo taken from the βa collected man" we...
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 ...