This is the same as Land Race but with waterborne craft. You have to race through checkpoints as fast as you can. For this challenge, you can use any vehicle of the same type as long as you unlocked them. If you're having problems getting the best time with the default vehicle, you can always try the challenge again with a different, much faster vehicle.
Unlock by: Liberate Olivo Moro
The course will take players through a narrow winding sea tunnel as well as tight turns with rings positioned near rockfaces. Good control and frequent use of nitrous is recommended.
Unlock by: Reaching the province after completing “Connect the Dots” story mission.
This is a very straightforward challenge though you’ll need a faster boat or nitrous to get a 5-gear time for this challenge.