In 2014 the author was allowed access to the annual winter exercise 'Clockwork'. Exercise Clockwork is the Commando Helicopter Force’s annual chance to test their mettle – and metal – in the harsh arctic winter of northern Norway. Following a winter in Norway, In 1968, where the limitations of HMS Bulwark’s Air group were keenly exposed, Flag officer Naval Flying Training (FONFT) ordered 846 Naval Air Squadron (NAS) to conduct trials and training in an Arctic environment in order to improve the aviation combat support provided to 3 Commando Brigade (3 Cdo Bde) Royal Marines. The NATO Northern Flank reinforcement plans, in which 3 Cdo Bde played an essential part, identified the Royal Norwegian Air Force Base (RNoAF) at Bardufoss as a key area, and it was here that the arctic training came to be centred. This book takes you-the reader- deep into the arctic to follow the UK Armed Forces during their annual cold-weather training. This book also takes a look at the early stages of the transition phase of the AgustaWestland Merlin HC.3/3A into Royal Navy service, replacing the venerable Westland Sea King HC.4.