Pirate Inc.

Hunt for the treasure of "Treasure Island" by R.L. Stevenson - two players try to evaluate the exact coordinates of this treasure.
There are 2 treasure charts - 1 player knows the latitude, the other the longitude of the buried chests on Treasure Island. They both land at the same time and spy on each other in order to try and find out the other's secret.

3 years later described in Reinhold Wittig's SPIELECOLLECTION No. 1 Spiele zur Schatzinsel (1988)
as "Seeräuber GmbH"