Back up for sale is my Seiko Tuna SBBN031. Purchased in Sept. 2017. Watch is in very good shape. Most of the obvious signs of wear are relegated to the caseback and the bracelet. There is a small, and dare I say difficult to perceive nick on the crystal above the first "M" in the Marinemaster text. You may be able to make it out in the photos below. I can only really see it if I have the watch pretty close to my face, and at certain angles and lighting situations. I could only bring out the nick if I had the camera flash on.
Only dived desks with these. Water has never touched the watch. Shroud was never removed. Alignment looks spot on with the bezel and chapter ring. Bezel rotation feels excellent. Crown engagement feels great. Seconds hand hits all markers perfectly. Clasp extender works as it should. Bracelet is currently sized for a ~6.75 inch wrist, and comes with three extra links. Ships full-kit, so box, manual, and signed papers. Also included is an Uncle Seiko Waffle Strap that I sometimes wore with it.
Price: $790 to U.S. buyers via Paypal. Shipping and Paypal fees will be handled by me. No trades. International buyers will be considered, but you must pay extra for international shipping. Any questions, please feel free to message me. Thanks!
Pic of the nick, clearest in the first shot. But as you can see, even with the flash, I couldn't even pick up the nick at certain angles.