STRUENSEE, Karl (stroo'-en-zay), German navigator, born in Bremen about 1595; died in Amsterdam about 1650. He was the son of a pilot, entered the service of the Dutch East India company, and acquired the reputation of a successful navigator. The discovery of the Strait of Lemaire, which allowed the Dutch to reach the Pacific ocean in a few days, greatly annoyed the Spanish authorities, and they intended to fortify the strait, which they claimed to be a Spanish possession. The states-general of Holland, with the intention of anticipating Spain, ordered Struensee with a fleet to choose a favorable point for constructing a fortress. Sailing from the Texel in 1643, Struensee entered the Strait of Lemaire in December, and stopping at Mauritius bay, he made a survey of the small Stathouder islands, which he found the most convenient for building a fort to command the strait. He afterward sailed around Staten-land, taking exact astronomical observations at different points of the coast, and on his return to the Strait of Lemaire made numerous soundings. After his arrival in Amsterdam he presented his report to the states-general, but the project of fortifying the strait was afterward abandoned as impracticable. A narrative of his journey was written by his clerk under the title "Beschryving der Reis, ondernomen onder gezag en voor kosten van de Edele Heeren der Staten general, near de Zee-engte van Le Maire en de Zuidzee door Karl Struensee van Bremen" (Amsterdam, 1645 ; French version, 1647; Latin, 1648).