Yes, I also knew S.R. Rao and I agree that he was a Hindu traditionalist. But I don't think I'd call him a Hindutvavadin since, if I remember correctly, and I may misremember, he was strongly against the right-wing politicization of archaeology.
The same was certainly true of a similar scholar, B.B. Lal, who opposed Hindutva politics.
I think it's valuable to retain the distinction between right-wing Hindutva politics and Hindu traditionalists who may believe in things like an antiquity of Hindu civilization far exceeding that accepted by the mainstream scholarly community but who do not support various right-wing political agendas.
But to return to my original question, which I did not expect to diverge into a discussion of politics. :-)
In addition to the submerged buildings off the coast of Dwaraka in Gujarat, there were reports of buildings seen off the coast south of Chennai when the waters receded during the tidal wave before they returned with a vengeance. Submerged buildings are common off the coasts of many countries due to the long-term rise of sea levels, so there's nothing controversial about it.
But I guess there hasn't been much follow-up that's known on this list. Dwaraka, of course, is also near Pakistan so I doubt the Indian government is going to want the Massachusetts Institute of Technology or Wood's Hole sending their research submarines over there.
Best,
Dean