Prudence Island History Mystery Cache

This should be an easy and informative puzzle on and about Prudence Island that hopefully shouldn't take you too long to solve. Getting there to make the find after you solve it will be a different story!

North 41° 36.[A+1][B+3][C+1] West 071° 18.[D+4][E-2]F

After a fallout with John Oldham, the native Narragansetts sold Prudence Island to Roger Williams and John Winthrop in 16FA with each man retaining a one-half interest: Roger Williams took the northern side of the island while John Winthrop took the southern side.

Development of Prudence Park began in 187D with the building of the Stone Wharf on the west side of the island which became a stop on the Fall River Line steamers running from Providence and Fall River to New York.

The Hurricane of 193C ravaged the island and severely damaged or destroyed many standing buildings located there.

In World War II, the U.S. Navy established an ammunition depot and base on the 400 acres on the southernmost part of the island. In 197E, the Navy turned the base over to the state of Rhode Island, leaving bunkers, roads, and a large deep-water pier.

Part of the 201B movie Moonrise Kingdom were filmed on Prudence Island as well as nearby Jamestown.

Certitude will provide information on the cache container and hide. Hope you enjoy!

You can validate your puzzle solution with certitude.