The provenance of the ship is indicated by the provenance of the keel. Westphalia (and northern Germany in general) was one of the regular timber sources for shipbuilding in the northern Dutch Republic (Maarleveld et al. 1994; Lemée 2006, 218, 256). The few observations on the hull itself are consistent with Dutch construction. When we convert the cargo’s encountered weight (550 to 600 tons) to 17th-century lasten of around 1975 kg (Hoving 1994, 40), it is 280 to 303 last. Although the relationship between length, beam and carrying capacity is problematic, it would fit a Dutch ship with a length of 37 m and a beam of 9 m (Hoving 1994, Tabel I). Witsen (1671, 100) gives a tableer for ships of 130 feet (36.79 m) and a width of 34 ft. (9.62 m), in which the keel length is 95 ft (26.88 m), which is the minimum keel length fitting the Aanloop Molengat remains. For their keel he prescribes two or three pieces of sound wood from Wesel on the border of Westphalia, 21 inches (53 cm) square in the middle, tapering to 15 inches (38 cm) in depth at the end. Narrower ships would be longer for the same capacity. The scantlings of the keel would equally be 21 inches (Witsen 1671, 72).
All in all there is good reason to assume that the ship was built in Holland. Nevertheless, construction in the northern German coastal area, which is underrepresented in the archaeological record (Maarleveld 1992; Stanek 2011), cannot be ruled out, even though a ship of 280 last at the very least is awkwardly large for the harbours on the Ems, Weser or Elbe.