A two stage multi.
The coordinates will take you to the Sea Dart plane at Sun n Fun. There you'll find an info board about the plane. You will need to answer the two questions to obtain the final coordinates.
A = What day in August did the Sea Dart become the first supersonic seaplane.
B = The 3rd digit of the Sea Dart's designation (4 digit number)
N 27° 58.A7B W 082° 0B.B7A