Besides the Sewer Sub with diver Don that will be released in 2014, the Turtle Sub will have a LEGO version
It looks like a sea turtle and is powered by Kinetic energy, with the result that the turtles must rapidly peddle on exercise bikes inside the vehicle to get it up to full speed.
The Turtles first used it to infiltrate an underwater Kraang Base guarded by a Sea Monster. It was continually attacked by the monster, though at the end the monster fellow in love with the machine. It then make another appearance in Plan 10 to infiltrate the Technodrome with Casey and April taking over Raph and Mikey's place peddlling on the exercise bikes.