Dutch Captain: Jan Jacobszoon Vlieger

This is from my translation of the entry in Dr. De Boer's book Tromp en de Armada van 1639 (1941):

Jan Jacobszoon Vlieger commanded a ship of the Zeeland admiralty, probably the Meerminne of 200 lasts and 24 guns. According to a note in Tromp's journal, Vlieger, along with Evertsen's squadron, joined the fleet on 2 May. On 16 May, he disappears, and Commandeur Pauwelszoon is listed instead, and is called to fight many times. Vlieger's ship shows on the booty list, although the name is omitted. Pauwelszoon now seems to have disappeared from the fleet. We are left puzzled by all this. On 16 September, in the margin of Tromp's journal, both Vlieger and Pauwelszoon are named, and there is one too many ships. In the ship list, the name of both has been added to the writing of Waterdrincker, but in the place of Vlieger is the name Pottebreecker, a known sailor who had distinguished himself several times before Dunkirk. Dr. De Boer suspected that Pottebreecker was a nickname for Vlieger, although he could find no proof that it was true. His assumption seems to be correct, nevertheless. See p.128 of Warnsinck's book Drie Admirals, and what it says about Vlieger and Pottebreecker.