T44 (Trident Basin Seaplane Base) in wrong location?

I am trying to fly to Trident Basis Seaplane Base (T44). In P3D flght planner, T44 shows on the map but when I actually fly to it I am still over land even tho the flight planner map shows that I am at the right location. I am using the default GPS in the Aerosoft Twin Otter Extended aircraft. I get the same result using FS-Flightcontrol.  If I set P3D to start the flight at T44, the aircraft is on the ground surrounded by buildings and trees.

Can anyone suggest a fix for this, or is there another way to have the aircraft location actually match up with the location shown on the flght plan map?

Thanks for any suggestions.

Martin Cook