Wristshot of a Casio G-Shock Frogman.
The pictured model is the "Final Frogman" GW-200Z-1JF.
The first Frogman model (DW-6300) was released in November, 1993. While Casio started to use a newer, four-screw back plate for its watches around that time, the DW-6300 retained the older back plate design. In June 1995 a second generation Frogman model was released, the DW-8200. From then on the Frogman became very popular under G-Shock collectors and many special editions have been released.
A unique model in the Frogman lineup is the limited edition MRG-1100-2. This model was part of the MR-G series, a high-end G-Shock line of metal watches. While all other G-Shock models are constructed with resin bezels and straps, the MRG-1100-2 is constructed completely of titanium.
In April 1999 the DW-9900 model was introduced. This Frogman was slightly smaller than the DW-8200. For the next two years both DW-8200 and DW-9900 models were produced. The DW-9900 seems to be a less popular model as it was soon followed up with the solar-powered GW-200 models in June 2001. Except for the "Snake Killer" and the "Carbon Fiber Frogman" (GW-201-6JF and GW-201NT-1JF), this Frogman has the Tough Solar 2422 module. The last GW-200 series Frogman is the GW-200Z-1JF "Final Frogman" that was released in November 2009. The model has been around for at least seven years, longer than the DW-8200. Typically, the "GW" designation refers to G-Shocks that can receive atomic signals, but no Frogman has been equipped with this feature prior to the release of the GWF-1000.
The GWF-1000 is the latest addition to the Frogman line, introduced on September 2009 in Japan. It represents the fifth generation of the Frogman series. The GWF-1000 is now capable of receiving atomic signals from six locations worldwide, while retaining ISO 6425 200 m water resistance, shock resistance, dive time measurement and solar power. It also incorporates a tide and moon graph function. Like the first generation Frogman, the GWF-1000 employs a stainless steel construction with the addition of diamond-like coating (DLC) to improve corrosion resistance.