Commando: Britain's Ocean Warriors

In a look at efforts to disrupt the supply of illegal drugs to the UK, we join a team of specialist commandos on a vessel in the Gulf as they prepare to deploy to board a suspicious dhow.

We also follow young officer Sam as he begins Arctic training in northern Norway, dealing with relentless conditions during his first trip north of the Arctic circle.

Change is afoot in this centuries-old organisation – new faces fill the ranks, women wear the green beret, and the force itself has new tech and advanced kit.

We look at the teams from Future Commando Force on a training exercise in Wales. This new force operates using small teams and is trained to work behind enemy lines to disrupt and destroy.

We follow Jerome, who is looking forward to both promotion and his impending marriage, Callam, who is juggling his home and work life, Donna, an army chef who dreams of becoming one of only three women in the commando ranks, and Danny, a captain and the force's only Rastafarian commando who recalls bitter hand-to-hand fighting in Afghanistan.

Amongst the true elite of the modern commandos are the Mountain Leaders. Known simply as the Cadre, they are the reconnaissance force of the Royal Marines, mountain and Arctic warfare specialists who are capable of operating deep behind enemy lines.

We follow Oli, who has always dreamed of becoming a member of the Cadre ever since he joined the Royal Marines five years previously. He had to come off an earlier course due to injury, and we join him as he faces brutal conditions, including a month-long climbing selection phase in Cornwall, three weeks of survival training on a remote Scottish island during Storm Arwyn and a 200km trek in the frozen north of Norway.