I looked at my copy of the recent book by Doeke Roos about the Evertsen family: Twee eeuwen varen en vechten 1550-1750. Het admiralengeslacht Evertsen. I had hoped that he might have had information about Johan Evertsen and Cornelis Evertsen de Jonge in the Battle of Scheveningen, but he did not. I also think that he may have several mistakes in the book, as well. The book indicates that Cornelis Evertsen de Jonge was captain of the hired ship Vlissingen in May 1652, but all indications are that he was captain of the Vlissingen Directors' ship Haes (30 guns) from May to July 1652. He also calls Cornelis Evertsen de Oude's ship, that was lost at the Battle of Scheveningen, the Wapen van Zeeland. All the original documentary evidence that I have indicates that the ship was commonly called the Zeeuwsche Leeuw (28 guns). In Vol.V of Schetsen uit de Geschiedenis van ons Zeewezen, Dr. Elias calls the ship the Zeeusche Leeuw, which is the name that I would expect to see.