There is at least some evidence that Jan Reijndersz Wagenaer's ship, the Graef Hendrick, was hired by the Groningen Directors. I had not been satisfied with any of the other candidate ships. There were certainly other ships hired by Groningen for service in 1652 to 1653, but they probably served under the Admiralty of Friesland. The two Harlingen Directors' ships, the Vergulde Pelicaen (28 guns) and the Sint Vincent (28 guns) were also considered under the category of Friesland and Groningen Directors' ships. The Vergulde Pelicaen was eventually discarded, but the Sint Vincent served up until being lost in the storm off the Texel in early November 1653.
The ship that I had long assumed was the Groningen Directors' ship, the ship of Joost Bulter, seems to have been bought for service under the Admiralty of Friesland. That ship was named Stad Groeningen en Ommelanden. That was one of two 38 gun ships listed in De Jonge's list for March 1653. The other was the Zevenwolden. The Stad Groeningen en Ommelanden came into service much later than the Graef Hendrick and the two Harlingen Directors' ships. The other candidate, the Groeninger Sint Nicolaes, also hired by Groningen, seems to have served under the Admiralty of Friesland and was commanded by Laurens Hermansz Degelcamp. I might be persuaded otherwise, but for now, I am listing the Graef Hendrick as the Groningen Directors' ship hired in 1652.