The Flash: Vertical Velocity (Six Flags Discovery Kingdom)

Steel roller coaster
the roller coaster at Six Flags Great America in Gurnee, Illinois

The Flash: Vertical Velocity (formerly known as V2: Vertical Velocity) is a steel Inverted Impulse roller coaster located at Six Flags Discovery Kingdom in Vallejo, California. It is California's first and only inverting Inverted Impulse Coaster, built by Intamin and opened on June 8, 2001. It stands 150 feet (46 m) and reaches speeds of up to .

When it opened on June 8, 2001, the ride was 186 feet (57 m). Both sides of the track were vertical, the front tower twisted and the rear tower straight with a reverse LIM segment at the top (designed to hold the train momentarily). In 2002, the ride was temporarily closed while the track was modified from 186 feet (57 m) to the city ordinance limit of 150 feet (46 m). To lower the height, the front tower was tilted to a 45 degree angle and the reverse tower lowered to 150 feet (46 m). Following the reopening of the park after its prolonged closure from the COVID 19 pandemic, The Flash once again was dormant, with barricades blocking the hill leading to the line in favor of a Mask Relief Area, where parkgoers could take off their personal masks if they so chose. The Flash's train was once again removed, this time going completely missing, whereas during the prior refurbishment to turn the coaster into The Flash, the train was disassembled and subsequently reassembled in the station.

The roller coaster's layout is akin to a large vertical U shape, that is loaded at the base and uses a series of LIMs to accelerate the train up each side of the track. One side of the track is twisted track (commonly called an inline twist) that ends in a straight section angled at about 45 degrees, the other side is a perfectly vertical straight track. The train seats 28 riders in an inverted roller coaster design.

2001 The Flash: Vertical Velocity opens as V2: Vertical Velocity. 2002 V2 is modified so both its towers are 150 feet, and its back tower has a 45 degree angle. 2007 V2 receives a repaint with red track & maroon supports. 2019 V2: Vertical Velocity is repainted and its track is given a darker shade of red while the supports become yellow. It is also given a retheme to the Flash and renamed "The Flash: Vertical Velocity.