Limited Edition. Tissot Watch Seastar 1000 Professional Limited Edition T1206141104100. The ISO 6425 norm certifies a use of watch in deep diving conditions. The watch can therefore be called a professional divers watch and is very robust with a water resistance up to 300m, screw down case back, crowns and pushers. For saturation diving, a helium valve is integrated in the patented bezel lock system, also allowing to completely lock the grippy bezel during the dive. The most powerful SuperLuminova currently on the market allows for an impressive readability in dark conditions.