In 1624 Vrolicq served as a harpooner for the Dutch Noordsche Compagnie, and the following year he represented two Basque whaling merchants who sent ships to Spitsbergen for a Copenhagen company.
When Vrolicq reached the northwest coast of Spitsbergen early in July he was promptly expelled by the admiral of the Dutch whaling fleet, Jacob Jansz Duynkercker.
In June, only a few days after their arrival in Port Louis, two English men-of-war, under William Goodlad, tried to expel Vrolicq and his ships, but failed.
Vrolicq again sailed in the St. Jacques, Harel in the St. François, Oulson in the Lion Rouge, Baptiste Girard in the Avenir (120 tons), and an unnamed fifth vessel.
[6] Following a Spanish raid which resulted in the sacking of St-Jean-de-Luz, Ciboure, and Socoa and the capture of fourteen French Basque whaleships in 1636, Vrolicq devoted himself to privateering.