The 3rd book in my trilogy is a speculative fiction novel about the people that used to live in this 9000 year old submerged city.
Although legendary in Tamil Nadu it was first spotted when the sea retreated 500 meters prior to the 2004 Tsunami.
http://www.ewao.com/a/legendary-ancient-temple-found-in-indias-coastal-waters/
ancestortrilogy 
This sounds really fascinating! I look forward to reading more! Good luck with your novel.
By the dark ghost of von Däniken! Very interesting.