Grand Seiko Watch Spring Drive Divers. The SBGA029 is a diver's watch that comes with a number of useful functionalities and Seikos Spring Drive technology. This timepiece is equipped with 9R65 calibre that utilizes elegantly the Spring Drive. It features a 72 hour power reserve. The case is both water and magnetic resistant. A power reserve indicator is available for the convenience of the wearer. Hands and markers are luminous for visibility in even the toughest of conditions. A date window is positioned at the 3 o clock mark. The timepiece features a uni directional elapsed time bezel. Additional functionalities include a screw crown, screw case back and scratch resistant sapphire crystal glass with anti reflective coating.