Why the eastern coastal plain does not have many good ports?
a. West coast is coast of submergence (except Malabar Coast) while east coast is an emergent coast. These imply that sea is deeper in west coast than sea on east coast. So, west coast has favourable conditions for natural harbours.
b. West Rivers form estuaries and eastern rivers form delta. Therefore it becomes difficult for ships to reach the east coast covered with sediments.
c. High Tides hit coast real hard. So coastal erosion, natural ports
d. Continental shelf on east extends up to 500 km into the sea, so, difficult to develop good ports and harbours. Ships can enter and leave only during tides. But this does-not mean we cannot have ports in this condition. Some of the world's well known ports are located on Continental shelves like London, Singapore, Hong Kong.
e. Historically, British India had trade contacts mainly with the Western world & Arabs. So natural choice was ports on western coast.
Geographically, the west coast is the submergence coast line barring the Malabar coast. Hence it has given rise to deep natural harbors as compared to east coast characterized by emergent coastline barring the coromandel coast.