Royal Navy

S1 E4: Heston boards the nuclear-powered Royal Navy sub, HMS Turbulent, to shake up the sailors' food. It's not long before Heston realises he's got a big job on his hands: the men are out on patrol for 90 days at a time, and they're eating three stodgy meals a day. And with so little opportunity for exercise on board, it's not a healthy diet - especially when the submariners' jobs require very high levels of concentration.