Episode: 1x01 | Airdate: May 8, 2011
The team uncovers the world of the giants that reside in and on our western seas.
A few metres off the Cornish shore, the team study Britain's largest fish, the basking shark. Despite the fact that they grow up to ten metres long, little is known about them, which makes effective conservation very difficult. In an exceptional encounter, the team is surrounded by up to 12 sharks as they feed on microscopic plankton.
Episode: 1x02 | Airdate: May 15, 2011
In the second programme in the series, explorer Paul Rose, marine biologist Tooni Mahto and maritime journalist Frank Pope explore the wild seas around Scotland.
The team travel to Bass Rock, one of the largest gannet colonies in the world. They are there to try and find out why, when most British seabird populations are in decline, the northern gannet is bucking the trend. Tooni helps scientists who are using GPS trackers to discover the extraordinary distances gannets can fly in the search for food. Paul goes beneath the waves to witness the amazing diving ability of Britain's largest seabird.
Episode: 1x03 | Airdate: May 22, 2011
This time on Britain's Secret Seas, the team set out to explore the waters off our eastern coastline, which are constantly pounded by the raw power of the waves. These are the shallowest waters off our shores but over the centuries they have been some of our most productive, providing oil and gas as well as fish for our tables. But things are changing in the North Sea and our team discover a sea full of surprises.
Episode: 1x04 | Airdate: May 29, 2011
In the final programme of the series, explorer Paul Rose, marine biologist Tooni Mahto and underwater archaeologist Frank Pope explore our busy southern shores.
