How to choose a G-Shock Mudmaster

Every Mudmaster is built for the same job: rough work on land, where dust, sand and mud get into everything. All of them have the mud-resistant button structure the line is named after, and all are water resistant to 200 metres. Where they differ is in size, how they are powered, how they keep time, whether they link to a phone, and which sensors they carry. This guide explains what each of those means, so you can decide which ones matter to you. The comparison on the category page lists every model against the same specifications.

Size and weight

Mudmasters are large watches. Their cases run from about 55 to about 61 mm long, measured from 12 to 6 o’clock including the lugs, and from about 16 to about 19.5 mm thick. Length and width decide how much of the wrist a watch covers; thickness decides whether it slides under a cuff.

The figures can pull in different directions. The battery-powered GG-B100 models are among the shorter cases but also the thickest, while the solar GWG-2000 is longer but thinner. The drawings on the category page show every case to scale inside the same circle, seen from above with its side profile, which makes these differences easier to see than the numbers alone.

Weights run from 88 g to 119 g. A heavier watch is more noticeable over a long day, especially on a smaller wrist; a lighter one can feel less substantial. Steel parts add weight: the GG-B100XM, with a stainless steel front bezel, weighs 104 g against 93 g for the otherwise similar GG-B100X with a carbon fibre bezel.

Size and weight are given for each family’s standard model. A few editions with other bands or bezel parts differ slightly.

Power: solar or battery

Most Mudmasters charge from light. Tough Solar models have a solar cell under the dial that tops up a rechargeable battery, so there is no battery to replace in normal use, as long as the watch sees enough daylight or indoor light. The GWG-1000, GWG-2000 (with its GWG-2040FR edition), GWG-B1000, GWG-100 and GSG-100 are solar.

The GG-B100 models and the GG-1000 run on a replaceable battery instead. A battery model needs no light to keep running, which suits a watch that spends long periods in a drawer or under a sleeve. The trade-off is a battery change every so often.

The comparison marks solar charging as yes or no, and you can filter by it.

Radio time sync

Models with Multi-Band 6 radio time sync set themselves from radio time signals, including the MSF signal broadcast in the UK, so they stay accurate without being set by hand. They receive the signal automatically when they are within range of a transmitter. Radio sync comes on the GWG models: the GWG-1000, GWG-2000, GWG-2040FR, GWG-B1000 and GWG-100. The GSG-100 has solar charging but no radio sync.

Watches without radio sync are set by hand, or, on the Bluetooth models, from the phone: the app can correct the time automatically several times a day. So a Bluetooth watch without radio sync can still keep accurate time, provided it is paired with a phone.

Bluetooth and the phone app

The GWG-B1000 and the GG-B100 family (GG-B100, GG-B100X and GG-B100XM) link to Casio’s phone app by Bluetooth. The phone app features row in the comparison lists what each one offers. Typical features are automatic time adjustment, about 300 world time cities, a mission log that records waypoints and their altitudes, automatic altitude calibration and a phone finder that makes the phone ring. The GG-B100 models can also send their step count to the app.

The phone link is useful if you want to change settings from the app, keep a record of a route, or have the time and altitude corrected for you. It does nothing without the app installed and paired, and all of these watches keep working as watches without it. Models without Bluetooth have no phone features at all, which some buyers prefer.

GPS and navigation

No Mudmaster has built-in GPS. The navigation to a set point row in the comparison therefore has two values: No, or Uses the phone’s location.

Models with Bluetooth have a location indicator: the watch shows the direction and distance to a saved point, working out its own position from the phone. The GWG-B1000, for example, asks the phone for its position every 10 seconds while the indicator is on, and refreshes the bearing and distance each time. This means the phone has to be with you, switched on and within Bluetooth range for the feature to work.

The saved point differs between models. On the original GG-B100 it can only be your current position, recorded on the watch, which turns the indicator into a way back to where you started. On the GWG-B1000, GG-B100X and GG-B100XM the point can also be set to any place on the map in the phone app. Models without Bluetooth have no location indicator; their digital compass, where they have one, shows direction but not the way to a point.

Sensors

Many Mudmasters carry a set of sensors Casio calls the Triple Sensor: a digital compass, a pressure sensor that works as an altimeter and a barometer, and a thermometer. The GWG-1000, GWG-2000, GWG-2040FR, GWG-B1000 and the GG-B100 family have all three. The GG-1000 has a compass and thermometer only, and the GWG-100 and GSG-100 have no sensors.

The altimeter works out altitude from air pressure, so its readings change with the weather as well as with height; it can be calibrated to a known altitude, and the Bluetooth models can do this automatically from the phone. The barometer shows pressure trends, which help to read a change in the weather. The thermometer reads the temperature at the watch, which is affected by body heat while you wear it.

The GG-B100 family adds a step counter. If you only need the time, the sensors add buttons and modes you may never use; if you walk, climb or work outdoors, they can stand in for a separate compass and altimeter.

Materials and build

The GWG-1000, GWG-2000, GWG-2040FR and GWG-B1000 have sapphire glass, which Casio describes as scratch-resistant; the other models have mineral glass. This matters most if the watch will be knocked about.

Carbon Core Guard is Casio’s name for a case made of carbon fibre-reinforced resin that protects the module; the GWG-2000, GWG-2040FR, GWG-B1000 and the GG-B100 family use it. Other models have a resin case with a resin and stainless steel bezel. Casio lists the GWG-1000 and GWG-B1000 as vibration resistant as well as shock resistant. The materials row in the comparison gives each family’s case, bezel and band.

Putting it together

Decide which of these features you will actually use, then filter the comparison by them. Someone who wants a watch that never needs setting or charging might start with solar charging and radio time sync. Someone who wants navigation help on the hill needs Bluetooth and a phone to go with it. Someone who wants a smaller or lighter watch on the wrist can sort by weight and compare the case drawings.

Some Mudmasters are not sold new in the UK. The category page shows only the models on sale here by default, and a checkbox in the filters shows the rest too. Prices given are recommended retail prices, not shop prices.