In 1498, Vasco da Gama, from Portugal, sailed towards India, southward along the west coast of Africa. He sailed in the largest ship of his times, Sao Gabriel that was 28 meters long. He writes in his log book diary, which is now in the Lisbon Maritime Museum that, when he came to South Africa, he saw Indian ships ten times the size of his own ship.
When we look at the ship sizes mentioned in the Nava Shastra, the Indian Navigational text, we see that there were indeed ships of the size observed by Vasco da Gama. From these measurements, it is obvious that India had large ships, with industries that built such large ships.
The making of these large ships prove that the Indian Shipping Industry was highly developed and formed the backbone of Indian trade then.
Unfortunately, the British destroyed Indian ship building industry to make way for the modern ships of the English, for their shipping industry and economy to prosper.