Casio has announced that its Royal Navy x G-Shock Frogman watch will be available from 7 April 2021, priced at £799.

The watch continues the collaboration with the UK's Ministry of Defence (MoD) and is described as "unbreakable".

It features design aesthetics inspired by British naval history, including the HMS Queen Elizabeth aircraft carrier, and is built using a Carbon Core Guard structure.

The watch is rated at ISO 200M so suitable for diving. Indeed, it is claimed that it is "water impenetrable".

There are no smartwatch features per se, but Multi-Band 6 automatic radio timekeeping is built in, but it can be linked to a smartphone for other basic connectivity functions.

You also get solar power and a tide graph - ideal for Navy use.

The face glass is made from sapphire crystal, while the hands are Neobrite luminescent. Other specific features include surface time measurement.

There is a rechargeable battery inside, with a claim of up to five months of normal use without exposure to light (on a submarine, say). It can last up to 30 months between charges in its power save function.

The Royal Navy x G-Shock Frogman watch weighs 119g and is part of a special edition collection, so likely to be available in limited quantities.