Vertical Velocity was closed for the start of the 2002 season while it was modified to be no more than 150 feet tell -- a height limitation imposed by the city. The forward tower was changed from a 90° vertical tower to 45° inclined tower. The rear tower remained vertical, but was shortened, presumably to 150 feet. How/why the Vertical Velocity was erected in excess of 150 feet is a mystery. Six Flags Great America in Gurnee, Illinois also built a identical Vertical Velocity for the 2001 season. While identical rides, the press releases differed by park - Six Flags Great America claimed a height of 186 feet while Six Flags Marine World claimed 150 feet.