Ark-19

The Ark-19 is an Autobot Starship in the IDW comics universe. The Ark-19 is the ship belonging to Prowl's detatchment on Earth. Hidden below a lake in Illinois, it acts as their headquarters on Earth.

(In the IDW comic universe there are many Autobot ships designated Ark. They are all presumably named after the first legendary lost Ark. They are differentiated by a number following the name. Hence: Ark-19)