This observational documentary series is filmed onboard the aircraft carrier HMS Illustrious during a four-month deployment. In the final episode of the series, the ship reaches the easternmost point of its journey; a nuclear submarine arrives for some training exercises; and, after 92 days at sea, Illustrious heads for home.

The mighty Illustrious aircraft carrier is nearing the end of its deployment. With a crew of 1,000, this 22,000-tonne floating city – nicknamed ‘Lusty’ – is home to all manner of sailors, from stewards to engineers, officers to deckhands. The ship’s mission is to support the Harrier jump jets currently serving in Afghanistan.

The man who has overseen the ship over the last four months is Captain Steve Chick, on his first mission in charge of an aircraft carrier. “Obviously, there’s an element of nervousness for anybody in taking command of a ship for the first time,” he says. “Getting to know the ship, getting to know how it handles, getting to know the people.” But Illustrious’s mission got off to a bad start, with a failed inspection and technical difficulties keeping her in British waters for some time.

Eventually, Lusty began its deployment and completed a successful trip to Malta, where the ship’s band and ceremonial guard put on a impressive display for the locals – and the crew took some well-earned shore leave. The next leg of the journey, however, was less straightforward.

Before Illustrious could enter the sun-soaked Middle East, it had to navigate the narrow 101- mile Suez Canal – and the ship’s company had to prepare for potential terrorist attacks. Located in a volatile region, much of this waterway is so narrow that Lusty could not turn around, making her a sitting duck for any attacks.

After a tense two days, Illustrious and her crew made it through the canal without incident and entered the relative safety of the Red Sea. On Lusty’s flight deck, sentries made way for sunseekers as the sailors prepared to let off some steam and party – military style.

This week, with the Harrier jump jets onboard and the ship’s stocks replenished, Lusty is heading to Goa – the easternmost point on the deployment. In a Navy tradition known as ‘hands to bathe’, the ship’s company gets a chance to cool down with a dip in the sea. All the intrepid swimmers have to do is avoid the jellyfish!

Before the pilots of the Naval Strike Wing leave Illustrious, they get to show off the amazing Harrier jets by performing vertical take-offs. As the pilots head home, Lusty is joined by a nuclear submarine, HMS Trafalgar. As well as providing the Illustrious crew with a glimpse of life onboard a sub, Trafalgar also engages Lusty in some valuable submarine warfare exercises.

Back above the surface, life goes on as normal. The assistants at Lusty’s medical surgery get some training sewing up pigskin; while father and son Kev and Olly Stoker compare their contrasting fitness levels. When the ship finally arrives in Goa, the sailors help out at a local charity before enjoying some downtime at a beach party. Then, after 92 days at sea, Lusty and her crew head home.