A badly injured sea turtle's prospects are looking up, thanks to a new prosthetic fin designed by an Israeli team and modelled on the wings of a US fighter jet.

The green sea turtle, named "Hofesh", the Hebrew word for "freedom", was caught in a fishing net off Israel's Mediterranean coast in early 2009. With his two left flippers badly injured, rescuers had to amputate, leaving him with a pair of stumps that made it difficult to swim.

The green sea turtle swims with a prosthetic fin at the Sea Turtle Rescue Centre in Michmoret, Israel. Credit:AP

Yaniv Levy, director of Israel's Sea Turtle Rescue Centre, said Hofesh was initially fitted with a diver's fin, but it provided little relief and he bumped into things as he tried to swim.

Shlomi Gez, an industrial design student at Jerusalem's Hadassah College, read about the animal on the internet and wanted to help. He designed a prosthetic based on a fish's dorsal fin. The contraption provided some improvement, but Hofesh still had trouble breathing and rising to the surface.