This is a Review that I wrote quite some time ago, but when posting about Following Fish, I remembered that Amitav Ghosh's In an Antique Land also dealt largely with Mangalore and its pre-British sea faring history.
The two threads of the story here focus on Mangalore and a Country that I lived in for 4 years - Egypt.
The description of Mangalore did not ring any bells, as it focussed mostly on the town as it existed 800+ years ago.
This is a book of non fiction. Amitav Ghosh chanced upon a letter between Abraham Ben Yiju, a Jewish merchant living in Mangalore, India, and Khalaf ibn Ishaq from Egypt, written in 1132AD. Part of this narrative focuses on Ghosh's search for more documents relating to Ben Yiju and part of the narrative tries to imagine the world that Ben Yiju lived in.
My entire Review can be read at http://karishmapais.blogspot.com/2010/02/book-review-in-antique-land.html