Rubber is the strap a dive watch is meant to wear, and on the Longines HydroConquest GMT L3.790.4.56.9 it makes everything lighter and more comfortable. The black dial, black rubber and ceramic bezel give it a stealthy, purposeful look that suits beach days, boat days and long flights.

The watch underneath is the full HydroConquest GMT. It is rated to 300 meters and runs on Longines’ exclusive L844 automatic caliber, whose 24-hour hand tracks a second time zone. Fitted with a silicon balance spring, the movement is about ten times more resistant to magnetic fields than the ISO 764 standard, and a full wind lasts around 72 hours. It is a modern, technical movement in a familiar diver design.

On rubber, the 41mm, 12.9mm-thick case feels noticeably lighter than on a bracelet. The strap rinses clean after salt water or a sweaty day, and it does not mind getting wet. The sunray dial still adds a little shine, so the look never turns too utilitarian.

HydroConquest GMT on rubber (L3.790.4.56.9) details

• Case: 41mm stainless steel, 12.9mm high, 21mm lug width
• Dial: black sunray with Super-LumiNova
• Bezel: ceramic insert on a unidirectional rotating bezel
• Caliber: Longines L844 automatic with GMT hand and date
• Power reserve: approx. 72 hours, silicon balance spring
• Water resistance: 300m, screw-down crown
• Strap: black rubber

Built for water and travel, and comfortable enough to forget you are wearing it. For a summer of travel, this is the version we would take.