A maintenance crew have to inch their way through a seaway obstacle course, a group of university students get a taste of navy life and a team of builders take on a challenging restoration two miles out at sea.

The Channel is a vast maritime highway with up to 500 vessels on the water at anytime, and it's a vital waterway for the British economy. The lighthouses and navigation buoys which help keep vessels from running aground are managed and maintained by an organisation called Trinity House, which was set up over 500 years ago by Henry VIII. The crew of their flagship vessel, THV Galatea, are carrying out urgent repair work on a buoy with a broken light and have to edge their way through an offshore windfarm.

The Channel has also long been a base and training ground for the Royal Navy in all its many roles. Over a winter weekend, a group of eager university students get a chance to experience naval life. They take command of HMS Smiter and HMS Puncher in a simulated counter-narcotics-and-people-smuggling exercise. When a real incident occurs, they learn first-hand that a life at sea can be unpredictable and hazardous.

While the Royal Navy are at the forefront of the modern-day military, in the middle of the Solent stand four Victorian sea forts whose defensive role is now defunct. Built in the 1870s to protect Portsmouth against Napoleon III's forces, the largest of them, No Man's Fort, is nearing the end of a multimillion-pound refurbishment to turn it into a luxury hotel - complete with 22 bedrooms, helipads, a sauna and cabaret bar. For the build team involved in the restoration, this particular work site has some unique challenges, particularly when it comes to hoisting two 26-stone hot tubs 60 feet up to the top of the fort. Show less