Here is the full list of all 17 Aqua Moto Racing Utopia (EU) trophies - there are 3 bronze, 4 silver, 9 gold and 1 platinum.
Complete all other Trophies
Own every watercraft
Win gold medals in Time Trial mode on every Track
Find the ball of straw at each Venue
Perform every stunt at least once in a race
Win every Ski Championship
Perform every air stunt at least once in a Freestyle Event
Win the gold medal in all Freestyle events
Perform every water stunt at least once in a Freestyle Event
Perform 20 stunts during a Freestyle Event
Win every Runabout Championship
In a Championship race, pass every buoy in 1st place and win
You must pass each buoy perfectly in a Championship race
Perform a Backflip with a Runabout watercraft
Win a Championship event
Jump over 40m
Complete the tutorial