Use waypoints to throw off your opponents intel.
Say you have an amphib tf at San Fran and are going to use it to invade Wake Island....
Set your "final destination" to, say, Sydney, Oz, but put your first waypoint one hex outside of Wake Island.
Then, while the tf is steaming to your first waypoint, the enemy intel should read something like "tf 1234 heading to Sydney" (or whatever is the proper syntax).... then, when you're a day's sail away from Wake, change your final destination to Wake Island.
Then the Japs won't know that you're coming.
Sneaky, I like it.