The 1982 Ford Capri was recovered from the bottom of the Regatta Lake at Holme Pierrepont Country Park, Nottinghamshire.
Police say the vehicle is likely to be stolen but tracing the owner could prove difficult.
DVLA records suggest it may have been below the water for more than 20 years.
Police diver DS Nick Sawdon said: “We turned up for a dive training day but as so often happens we got a call and it was an unusual one.
“The recovery was quite a challenge so we had a pretty good work out for our training day. It was half full of sand so we had to use lifting bags and winches to recover it.”