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 Spiraling Impulse Coaster, built by Intamin and opened in 2001. It stands 150 ft tall (46 m) and reaches speeds of up to 70 mph (110 km/h). The ride is tied with Medusa and Superman: Ultimate Flight in the same park for tallest roller coaster in Northern California.