Off the coast of Yorkshire, Siwrengale is heading out for the beginning of the North Sea whelk season. Skipper Darren Warters is on the hunt with sons Regan and Lewis. Asian demand has created a lucrative fishery in this small patch of the North Sea, but winter storms have badly damaged their pots. Miles of rope must be untangled before they can begin fishing in earnest.

South east of Shetland is ‘Long Hole' - the deepest waters in the North Sea. Reliance III is the only boat for miles around. In this secret spot, skipper John Clarke is hunting for whiting. But the whiting trade is one of the most volatile in fishing. When his grounds are discovered by rival boats, John is forced to move on.

Endeavour 5 is far off in the North Atlantic, hunting for squid along the continental shelf. The brand new £8m boat was part-financed by a huge bank loan and built to withstand the toughest conditions off Scotland's west coast. When the squid prove elusive, the pressure starts to mount. But could the arrival of a winter storm see Endeavour's rivals forced back to harbour, giving it a monopoly over the squid grounds?

300,000 square miles of ocean. Three GPS-tracked voyages, filmed around the clock. One week at sea.

Crabber Tydus has had a terrible year, missing months of fishing due to breakdown. With the boat finally fixed, skipper Stiggy pushes the crew to work around the clock to fill the tank with ten tonnes of crab. After covering expenses, Stiggy gambles and moves his pots further south. Can Tydus overcome injuries to its crew, and can Stiggy keep the boat bodged together to finally pull off a profitable trip?

Trainee skipper Michael Bruce is learning the ropes under his father, experienced trawler skipper Peter Bruce. Their boat, Budding Rose, fishes as a pair trawler, towing a large net in close-proximity with a second trawler. Hunting for white fish in the North Sea, Michael takes the
wheel in bad weather and must prove himself by manoeuvring the boat within throwing distance of the other vessel if they are to connect the nets.

Strong tides have kept the Newlyn netting fleet in harbour for the past ten days. One boat, Karen of Ladram, is first out ahead of the competition. The first boat back with a haul of hake will have a monopoly at the market and could double their prices. But the trip is thrown into jeopardy when a crew member's health deteriorates, and their catch is decimated when seals get to the fish first.

Sharon Vale is hunting for haddock in the Irish Sea, with rookie deckhands Raj and Damon from India. Teaching his new recruits on the job, skipper Trevor Annett heads to ‘the peaks' - a treacherous undersea ridge of rock, but a haven for haddock. Will the gamble pay off?