The ship was meant to commence trials on the day the Germans invaded, and to prevent her capture the "Heemskerck" was immediately pressed into service. Since she had no armament she left port for the United Kingdom with only a skeleton crew. Once she had arrived in Portsmouth attempts were made to give her weaponry of some sort. She received depth charge equipment from the old torpedo boats "G13" and "G15". On 18 May 1940, Queen Wilhelmina paid the ship a visit. At the end of the month, "Heemskerck" and the cruiser received the assignment to transport Princess Juliana and her two children (including the later Beatrix of the Netherlands) to Canada. The ships put to sea on 2 June and arrived on 11 June at Halifax.