I had mistakenly called Teunis Post by the name Teunis Poort. He was originally schipper of the Vlissingen Directors' ship Arend (or Dubbele Arend) . Yes, the Dutch name is the origin of the name skipper in English. I first saw Teunis Post mentioned as having attended the council-of-war on the Brederode on 6 August 1652, after the storm in the Shetlands. By December 1652, we see him commanding the Arend, and by sometime in 1652, he was appointed kapitein of the ship.