Chronograph functions on a dive watch are not just decoration here. The Tissot Seastar 1000 Chronograph in blue lets you start, stop, split and accumulate times while still sealing the case to 300 meters, and it does so with a dial that changes from cobalt to midnight as the light moves across it.

The 45.5mm case is large and sporty, balanced by a 12.82mm profile that is reasonable for a chronograph diver. Two subdials track 30 minutes and tenths of a second, the center hand handles chronograph seconds, and a date sits neatly in the layout. The ADD function lets you add separate timed intervals together, while SPLIT freezes an intermediate time without stopping the run, useful for anything from laps in the pool to timing a recipe.

A Swiss quartz movement keeps it precise and easy to own. The steel bracelet releases from the case without tools, so you can swap it for rubber when the watch heads to the water.

Blue Seastar 1000 Chrono T120.417.11.041.01: What You Get

• 45.5mm stainless steel case, 12.82mm thick
• Blue gradient dial with luminous hands and markers
• Swiss quartz chronograph: 1/10 sec, 30 min, ADD and SPLIT
• Screw-down crown and pushers, screw-down back
• Rotating dive bezel with aluminum ring
• Sapphire crystal, double anti-reflective
• Quick-change steel bracelet, safety folding clasp, diver extension, 22mm
• 300 meters water resistant

Precise timing, deep water, and a dial that never looks the same twice.