By coincidence he was able to take over a ship of 200 tuns, 17 canons and 80 crewmen. After 1621, Compaen sailed away with a Letter of Marque of the Dutch Admiralty leaving them to pay for the remaining sum of f. 8.000.- he still owed the widow of the previous owner Captain Pieter Gerritszoon of Medemblik. The first ship he attacked was a fishing boat. He took in some fresh Herring and salted fish, but "payed" with an letter of credit for the Dutch Admiralty te Hoorn. They refused to pay the fisherman, however. After taking another ship and distributing the goods amongst his crew he sailed to Vlissingen (on account of a storm) where he took on 50 more crewmen. After leaving Vlissingen he became a pirate. He did not attack ships from England and the Barbary coast, however, because he needed some places where he could sell the captured ships and their cargo.
In 1625 he went to the Irish coast, to the Duchy of Clare. The Governor of the area was apparantly a good friend of him. The Earl of Stafford, Thomas Wentworth, was also a close friend of Compaen. For some time he was active in the Irish sea until it became too dangerous and he had to leave. He sailed to the Mediterranean sea where he continued to attack and capture ships. He sold the ships and/or cargo at the ports of Saffi, Mogador and Salé which are located on the coast of Morocco.
At Salé he sold many of the captured prizes initially to Simon the Dancer Jr.. He was the son of the famous corsair Simon the Dancer who had also been active as a dealer in stolen goods for a time. Simon Jr. charged heavily for his services and this was the reason why Compaen eventually switched to Jan Janszoon. Simon Jr. was very unhappy about this and at some point even attacked Compaen. Compaen was forwarned and was even able to capture one of the attacking ships. Another ship, with Simon Jr. on board, was so severely under attack that it had to flee. Simon Jr. fled to the Dutch Republic where apparantly he got a pardon. He sailed from the port of Vlissingen in 1627 and 1628 with a Letter of Marque.
On the 5th of July 1626, while Compaen was actively pursuing a pardon from the Dutch Republic, he attacked a Dutch ship of the VOC (= Vereenigde Oost-Indische Compagnie, transl.: East India Company), called Hollandia, that was accompanied by the smaller ship the Grootenbroek. The attack cost Compaen over 70 of his men and his ship was also heavily damaged so that he had to flee with his four ships.
The Hollandia had been part of a fleet that was on its way to the Cape of the Verdian Isles, but due to a leak it was on its way to Sierra Leone for repairs, accompanied by the Grootenbroek, while the remainder of the fleet sailed on. Heavily damaged by the attacks of Compaen it managed to sail into the port of Sierra Leone. The 4 ships of Compaen meanwhile guarded the port to prevent the escape of both ships. After some time Compaen also sailed into the port for repairs, but Both VOC ships kept a wary eye on him during his stay. When the repairs were finished he sailed away without being attacked by the three ships of Compaen that had cast out their anchors outside the port. Both the Hollandia and the Grootenbroek eventually reached Batavia in December 1626.
Compaen, like many pirate Captains, had often great difficulty in keeping the peace on board of his ship. This situation was sometimes even more difficult on account of heavy drinking or regular shortages of supplies. In one instance Compaen attacked a Spanish settlement because he had insufficient supplies. Unexpectedly, The Spanish settlement was too strong for him and he had to leave with heavy losses and without the extra supplies.
In another instance it seems he was also roaming along the Spanish coast. He met with and fought against the pirate Colaert of Duinkerken. Despite being outnumbered 4 to 1 Compaen still managed to get away from Colaert when he turned out to be stronger.
In 1626 or 1627 Compaan arrived in the port of Salé with newly captured prizes. Word of a pardon awaited him there (1627) which he accepted and sailed to the Netherlands. Just in time it would seem, because a Dutch fleet that was looking for him arrived four days later in Salé. After dropping off a number of his crew in Ireland he sailed to Vlie. He got his pardon from Prince Frederik Hendrik in the Hague. In the few years that he was active as a pirate he was able to capture several hundreds of ships. He did not fare so well on Land though: he died in poverty on February the 25th of 1660 in Oostzanen.