Eualos ago

Astronomical I'd imagine.

SpottyMatt ago

Ships are not small things. How did pirates get their start pirating? Where they mostly ex captains that had been put in charge of a ship (during the course of their duty in military or employ with a merchant company) and decided to turn pirate? Where they mostly wealthy individuals that decided it would be fun to buy a ship and be a pirate?

Were ships common and plentiful enough back then that it was actually not as hard as I'm imagining to get a hold of one suitable to be a pirate vessel?