Samsung Captivate :: Google Maps Downloading

i took the captivate on the road and used it as navigation. it worked great for the first 3 hours of the trip, reception or not. i was amazed until i received a notice that my phone internal app memory is low and i need to uninstall my apps. theres no way my memory should be full because i've checked it every few days and i've had 1.6 gb free. all of a sudden i've got 126mb. i'm guessing that Google maps had downloaded the maps in advanced and had just filled up the internal memory. unfortunately i have no clue how to clear the maps. until i can figure this out i cant receive emails, or texts or any messages because the memory is full. does someone know how to clear the old maps from the navigation app? i'm on the road so i havent been able to look at it extensively. i will research it more when i get a chance and post anything i find.