Up for sale is my Seiko 6159-7010 Professional 600m, better known as the Grandfather Tuna — the very first of Seiko’s saturation-rated shrouded divers and one of the more historically important dive watches. This is an excellent example for the Seiko enthusiast. I imported this directly from Japan. This is a 1975 original from March which is likely one of the earliest examples you will see. It also lacks the “m” in 600m. Features a titanium case, ceramic shroud, monocoque construction, original dial/hands, and the legendary 6159B hi-beat (36,000 bph) diver movement. ⸻ Key Details - Model: Seiko 6159-7010 - Case: Titanium monocoque construction - Shroud: Original ceramic-coated shroud with proper slotted screws - Movement: 6159B hi-beat automatic, 36,000 bph - WR Rating: 600m (not tested due to age) - Dial: Original “Professional 600” dial with beautiful even patina - Hands: Correct original set (no aftermarket lume) - Crystal: original (excellent) - Bezel: Original insert with natural wear, turns smoothly Caseback: Correct 6159-7010 engraving with matching serial (1975) Strap: Comes on current worn rubber strap + includes original vintage Seiko rubber strap shown in photos. ⸻ Condition Overview - Dial: Amazing — deep matte black with rich, even warm patina across all lume plots. No moisture marks or edge degradation. - Hands: Original and matching. - Shroud: Original with honest wear at edges, no cracks, no replacements. - Case: Sharp, clean titanium with expected vintage marks but no abuse. - Bezel: Original insert with typical fade/chipping at edges. - Crystal: Excellent Function: Running extremely well and setting properly. Service history unknown and timegrapher can be provided. Caseback: Excellent engraving clarity; correct early serial. This is a collector-grade, unmolested example, exactly what serious Tuna buyers look for. 3500$ shipped located in Houston TX