The GBX-H5600 is where two threads of Casio's lineup finally converge. The GBX-100 brought the G-LIDE's surf credentials — tide graphs, moon data, MIP LCD — into the 5600 square case. The DW-H5600 brought optical heart rate monitoring and Polar-backed training analysis to the same form factor. The GBX-H5600 combines both into a single watch, and in doing so becomes the most capable 5600-series G-Shock Casio has produced. It's also the first G-LIDE with a heart rate monitor — a complication the surf-oriented line has been missing. The signature visual detail is a translucent resin bezel that exposes the watch's internals through a tinted see-through layer, available in black and blue band configurations.

The case measures 51.1 x 44.5 x 17.3mm and weighs 47 grams — meaningfully lighter than the DW-H5600 it builds on, thanks to a carbon fiber-reinforced resin caseback replacing the stainless steel used on earlier heart rate-equipped models. Key resin components in the bezel, case, and band are made with bio-based resin, a material expected to reduce environmental impact. The MIP LCD is the right display choice for a watch meant to be worn outdoors: high contrast, wide viewing angle, and legible in direct sunlight without burning through battery. Water resistance is 200 meters, and the watches are suited for coastal sports like surfing. 

Powering the 3586 module inside is a hybrid system: USB Type-A wired charging and solar-assisted charging, where solar handles timekeeping when the battery is low, but wired charging is needed for frequent heart rate monitor and connected feature use. Battery life runs to approximately 35 hours with activity tracking active, one month in basic watch mode, and 11 months in power-saving mode. On the fitness side, Polar handles training analysis — Running Index, Cardio Load, Energy Used, and Nightly Recharge — alongside sleep tracking, blood oxygen measurement, and guided breathing. On the G-LIDE side, 50 preset surf ports are available directly on the watch, with up to 3,300 points accessible via the Casio Watches app, along with the option to specify any user-defined location. World time covers approximately 300 cities via smartphone link.