Fluid Effects > Pond > Add Boat Locator

 
 
 

Boat locators follow the motion of the pond the Y direction, but additionally rotate in X and Z to allow the boat to pitch and roll in the wake.

Fluid Effects > Pond > Add Boat Locator >

If you want to move the position of the locator interactively, the locator cannot be connected directly to the expression. In this case, turn on Free Transform.