Greek and Roman ships
The old Roman and Greek empires were pirating about 1,500 years ago, The sea around Greece was filled with a lot of small island, the pirates carrying valuables sailed through the island, they traveled close to the shore that was easy for the pirates, who were hiding they treasures on the island
Greek ships
The Greeks pirates used a streamlined ships to attack, the name of this ships was "galleys", they was so powerful. Depending on the size of the pirate ship, dozens of pirates crewmen rowed the ship.
A "galley" with a lot of man was to much faster than the cargo ships that depend on the wind power.
The "galleys" was easy to control they could quickly change direction, it also mean that if the pirates were being chased, they could escape to shallow waters.

Roman ships
Romans were not natural seamen like the Greeks, so they took the idea of their ships from the Greek ships. Romans also use powerful "Galleys" with a long oars. Some of this galleys had more than one level on the ship. The poor oarsmen who rowed below the deck were forced to row where it was hot and stinky.