Justin Bieber Feels Need For MORE Speed On Jet Boat

Justin Bieber was so totally unimpressed by something called "the world's most exciting jet boat ride" -- and it was written all over his face.

The Biebs had Monday off from his tour and hopped on a Shotover Jet in Queenstown, New Zealand. The high-speed boat hits 50 mph while careening and doing 360 turns. If that sounds like it'd be tons of fun ... it probably is, unless you're Justin.

Occupational hazard for a guy who drives exotic sports cars, we guess.

JB rented out the entire boat for himself and his 2 pals, so at least he was bored in private.