It was a terrapin the size of a dinner plate located on the Nottingham canal near to Boots industrial estate!
I did a spot of reading up on the Waterscape website...
"Originally native to the UK some 8,000 years ago, the terrapin has made a fateful return to our waterways in the aftermath of 1980s 'turtle mania'.
Tiny baby terrapins, roughly the size of a 50 pence coin, were once thought ideal pets for youngsters in thrall of the Ninja Turtle cartoon heroes. Consequently, aquarium tanks became a common feature of many British homes.
Today, these pets have grown to the size of a dinner plate and developed enough strength to break free of their tanks. Their subsequent, and irresponsible, release into the wild has prompted fears for the health of local wildlife, as well as the terrapins themselves who are ill-equipped to survive in the damp British climate.
Terrapins, along with tortoises and turtles, are known as Chelonians - reptiles with shells. They are almost totally aquatic but also need dry land to bask on during sunny days. Still waters and rivers in the Midlands and Southern England support the largest terrapin populations. These are largely made up of American red-eared terrapins, although snapper turtles and European pond terrapins have also been spotted along our waterways. It is unlikely that these animals are breeding, as terrapin eggs need to be incubated at 25 degrees Celsius for around 60 days in order to hatch"
Facts
Appearance: Similar in colour and appearance to a tortoise. Red-eared turtles can easily be identified by the red stripes on both sides of their head
Size: Adults can reach 40cm
Weight: Up to 2kg
Lifespan: 30 years
Diet: Terrapins are omnivorous and will eat a variety of fish, worms, small animals, snails and vegetation
Family: Testudinidae
