Commander of the fluit Graaf Willem, later in 1653

Captain Jan Coenders commanded the hired fluit Graaf Willem in the Battle of the Gabbard. He was judged to be too inexperienced in war for further service. His luitenant, lt-cdr Hessel Gerritsz Bertson, is mentioned in a retrospective list from 22 November 1653 as commander. The Graaf Willem was a large 26-gun ship hired by the Admiralty of Friesland.

Some Rotterdam guns from 1615

I have not seen that many cases where there are the weights of guns listed, but I recently received pages that had gun weights for Rotterdam guns from 1615:

24pdr 4473 pounds
24pdr 4616 pounds
12pdr 3180 pounds
12pdr 3131 pounds
 8pdr 2070 pounds  bronze
 8pdr 2060 pounds  bronze
 6pdr 2186 pounds
 6pdr 1584 pounds
 5pdr 1600 pounds
24pdr 2480 pounds Spanish chambered piece
18pdr 1400 pounds chambered piece
 4pdr 1400 pounds bronze
 3pdr 1000 pounds bronze
 

What ship did Pieter Aldertsz command in the first part of 1652?

I have some trouble believing that Pieter Aldertsz commanded the Hoorn (32 guns) prior to August 1652. I have the list from 30 June 1652 and the list of ships from Hendrick de Raedt's pamphlet from the voyage to the Shetlands that clearly show that he commanded a ship armed with 24 guns, as if this was one of the smaller, 116ft ships, such as the smaller Enkhuizen. He definitely commanded the larger Hoorn, a 120ft ship, from late 1652 to when he was killed at the Three Days Battle. His brother Claes Aldertsz commanded the Hoorn after that for the rest of the war, I believe.

21 September 1652

I have an interesting list dated 21 September 1652. This is a list of ships of the Admiralty of Amsterdam. The list has ship names, commmanders, guns, crew, and victuals (months or weeks). A nice feature is that the list has the names of Watt convoyers and fireships, with their commanders.

The supposed 226 ships in 1652

The plan for equipping the Dutch navy in 1652 called for 226 ships: 40 convoyers funded at the peace treaty in 1648, 36 cruisers funded in 1651, 50 Directors' ships funded in 1652, and 100 ships to be hired by the admiralties in 1652. I have not seen these figures mentioned after December 1652. In fact, there were never this many ships hired at one time. There seem to have been fewer than 40 convoyers left by April 1652. All 36 cruisers were in service by then. It may be the case that all 50 Directors' ships were hired and in service by about May 1652. Almost immediately, two were lost. The Sint Laurens was captured by the English on 29 May and the Erasmus was sunk in June. There is a debate over whether there was ever a Directors' ship hired by the Stad en Lande or Groningen. The admiralties were never able to provide the 100 ships. Many were soon lost or discarded, so that by December the total had fallen well below the eighty-some actually hired. By June 1652, the the lists seem to be jumbled, in that ships that had served an admiralty were listed as Directors' ships and ships were listed under different Directors.