There are reports that pirates cooperate with each other to seize ships.

VOA: special.2009.05.27

So fruitful is their land that they are spared the evil necessity of traveling on ships and there you have an interesting point about the Greeks.

他们的土地丰饶,这一切让他们远离了航行的厄运,这时你会发现关于希腊很有趣的一点

耶鲁公开课 - 古希腊历史简介课程节选

In the 1630s there are 2,500 trading ships.

630年,这里大概有两千五百艘商船

耶鲁公开课 - 欧洲文明课程节选