The Greek author of the "Periplus of the Erythraean Sea," who wrote in the first century of our era, mentions the pirates infesting the coast between Bombay and Goa.

Two hundred years before Vasco da Gama had shown the way to India by sea, Marco Polo had told Europe of the Malabar pirates.
"And you must know that from this Kingdom of Melibar, and from, another near it called Gozurat, there go forth every year more than a hundred corsair vessels on cruize.

These pirates take with them their wives and children, and stay out the whole summer.

Their method is to join in fleets of 20 or 30 of these pirate vessels together, and then they form what they call a sea cordon, that is, they drop off till there is an interval of 5 or 6 miles between ship and ship, so that they cover something like a hundred miles of sea, and no merchant ship can escape them.

For when any one corsair sights a vessel a signal is made by fire or smoke, and then the whole of them make for this, and seize the merchants and plunder them.