Seiko Prospex Marinemaster Professional 1000m Emperor Tuna SLA042

Seiko's Tunas are its shrouded, can-shaped divers, and the SLA042 (SBDX038 in Japan) is the automatic 1000 m model, which Fratello's writer ranked first among the Tunas he would buy in 2023, singling out its rose-gold-plated details against the titanium and ceramic. The shroud is ceramic, fitted over a one-piece titanium case that loads from the front, so there is no separate caseback to seal, and Seiko rates it for saturation diving. It is a large watch at 52.4 mm across, 17.4 mm thick and 53.5 mm lug to lug, and weighs 158 g on its 22 mm silicone strap. The movement is the 8L35, which Fratello notes descends from Grand Seiko: a 26-jewel automatic beating at 28,800 an hour, regulated to between 15 seconds fast and 10 slow a day, with a date and about 50 hours of reserve.

Written 10 October 2026 from Seiko's product page (Middle East) and Fratello's Tuna buying guide.