Saw this watch on the internet. Designation is Seiko Professional Diver S23619J1. Looks like a Tuna but doesn't have the "Marinemaster" on the dial. What's the difference?
Seiko Professional Diver (s23619j1) - Seiko Watches
Seiko 1000m Shrouded Diver – S23619J1 « Yeoman's Watch Review
Anyone have any more info on this watch?