The Seiko Prospex Polygonal Coastline - Cobalt Men's Watch is perfect for adventurous men. Whether you're diving underwater or going about your daily routine, this watch is up for the task. It has a 300m water resistance, so it can handle deep dives. The watch runs on the 6R55 automatic caliber with a 72 - hour power reserve. It has a scratch - resistant sapphire crystal and a secure clasp for long - lasting use.