A software tool has been developed to simulate the entanglement of leatherback sea turtles (Dermochelys coriacea) in fishing and aquaculture gear. Entanglements are well documented and are increasing in frequency due to greater fishing effort and with the use of synthetic materials in marine applications. However relatively little is known about how entanglements occur and how they might be prevented. The objective of the present study is to develop a computer simulation model, using the software program MSC Adams, to realistically mimic the behavior of adult leatherback sea turtles as they become entangled with a mooring line. Such a tool can assist designers to develop and advance mooring and fishing line technology to reduce the number of leatherback turtle entanglement events.