Aware of that... closest POI are gas station, gas station warehouse, Train Station and Airport Terminal and they are 5 or more miles further inland.. I just posted it because I find it funny to see a boat travelling across the land. Have even had same thing happen where the POI is a Forest. We were told earlier that the game does not know land from water (understandable) so nothing can be done. It is definitely an issue as It seems funny...but not a complaint
If you dont have your settings set to use only your own POIs then it'll also spawn based on whatever random POIs someone else put down.