The close diplomatics tie between the Song dynasty of China and the Medieval Cholas facilitated
*The famous Chola ship-designs employing independent water tight compartments in the hull of a ship.
*The mariner's compass
*Dharani - The equivalent of modern-day destroyers designed to take combat to high-seas.
*Loola - The equivalent of modern day Corvettes ; designed to perform light combat and escort duties.
*Thirisadai - Probably the battle cruisers or battleships of the day, they are reported to be armored heavily and could engage more than 2 targets in combat, and relied on its built rather than speed to survive
Apart from class definitions, there are names of Royal Yachts and their architecture.
*Akramandham - A royal Yacht with the Royal quarters in the stern.
*Neelamandham - A royal Yacht with extensive facilities for conducting courts and accommodation for hi-officials/ministers.
In addition to these, we find many names of Ship classes in Purananuru and its application inboth inland waters and open oceans. Some of them are,
*Kalam - Large vessels with 3 masts which can travel in any direction irrespective of winds.
*Patri-Large barge type vessel used to ferrying trade goods.
*Oodam -Small boat with large oars.
*Ambi -Medium sized boat with a single mast and oars.
*Toni - small boat used in rocky terrain
Boat seems quite sophisticated with a pavilion at the center of the boat/ship
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