Casio says its EX-G1 camera, set to launch in January, will be the slimmest waterproof, shockproof model on the market.

A 12.1Mp digital camera with 3x optical zoom, the Casio Exilim EX-G1 will be a scant 19.9mm thick. Casio has tested the EX-G1 and says it is fully waterproof to a depth of 10 feet and will be able to be used underwater for up to an hour before needing to be dried off. It can withstand temperatures as low as -10 degrees C.

Intended for use by extreme sports enthusiasts who may not wish to stop what they're doing to compose a shot, the EX-G1 has an interval shooting mode that allows the user to pre-compose and automatically take a series of shots. This means you could strap the camera to your body and capture the action as you go. Intervals of 10 seconds, 30 seconds, 1 minute or 3 minutes can be set. An equivalent mode for video capture can be used to automatically shoot for between three and 30 minutes.

More standard features of the Casio EX-G1 include a best shot function that fires off several frames rather than a single one and then suggests the best of them to keep. This can be useful for capturing more natural portrait shots as well as improving the chances of getting a good action shot. Photos are stored to microSD Card or a microSDHC Card, but there's also a 35.7MB internal memory.

Preset scene modes on the £279 camera include ones for snow scenes and beach scenes. ISO light level adjustments from 64 to 3200 will be user-selectable. The rechargable lithium-ion battery is CIPA-rated to take 300 shots between charges. With its battery installed, the EX-G1 weighs 154g.

The camera will be available in a choice of red, silver or gunmetal grey and will be sold through, Casio's online store.

Casio Exilim EX-G1 waterproof camera