Casio Pro Trek PRG-300

The PRG-300 uses Casio's Triple Sensor setup for an altimeter, barometer and thermometer, and digital compass, powered by Tough Solar. Casio lists 100-meter water resistance, so it suits hiking and general outdoor use but is not a dive computer. [Casio PRG-300 specifications](https://shop.casioca.com/products/archive/watches/pro-trek/prg300-1a2)

Its Tough Solar system recharges from light, so routine operation is not based on replacing a disposable battery every few years. It still contains a rechargeable power cell, and long storage in darkness can reduce the charge, so regular light exposure matters.

The PRG-300 is rated to 100 meters, which is appropriate for swimming and surface-water activities when the watch is in good condition. That rating is not the same as a 200-meter dive watch, so scuba use should be judged by the exact Casio manual and service condition. [Casio PRG-300 specifications](https://shop.casioca.com/products/archive/watches/pro-trek/prg300-1a2)

The PRG-300 is the simpler digital Triple Sensor option with 100-meter water resistance, while the PRW-70 adds 200-meter resistance, Multi Band 6, tide and moon data, and a fishing-time function. Choose by use: hiking points toward PRG-300 simplicity, while water and fishing features point toward PRW-70. [Casio PRG-300](https://shop.casioca.com/products/archive/watches/pro-trek/prg300-1a2) [Casio PRW-70](https://www.casio.com/jp/watches/protrek/products/prw-70/)