Test rides on the new Diamondback roller coaster at Kings Island are now underway. Diamondback is the tallest and fastest coaster at Kings Island. The ride stands 230 feet at its highest point with a first drop of 215 feet at a 74-degree angle. Diamondback has 10 vertical drops overall, including drops of 193, 131, 129, 110 and 106 feet; two helixes and a splashdown ending. Riders will snake their way around 5,282 feet of track in excess of 80 miles per hour. The $22 million steel coaster opens April 18.