Speed Boat performance stats:
Speed Boat: Speed 4.0; Acceleration 4.5; Endurance 2.0; Handling 4.0 (per p. 77 of Prima Game Guide)
This is as opposed to the fishing boat:
Fishing Boat: Speed 3.0; Acceleration 3.0; Endurance 1.5; Handling 3.5 (also p. 77 of Prima Game Guide)
Boats are such a great way to evade police chases if you can handle the helicopters. The police do not have boats. So, if you can disable the helicopter twice, and get outside the circle or wait for the chase time-out, then you are good.