Adam's bridge is now an archipelago that stretches from Sri Lanka all the way to India.
This area has a couple of military bases but you can walk really far out onto the archipelago by skirting the coast.
Follow the sign from the road for the view point. When you get to the water you follow the coast round to the left. You'll come to a little hut with a guy sat in it, you'll need to wait through shin-knee deep water to get to the archipelago from there.
You can keep walking past the outpost onto the huge beach area and its almost always deserted. Its often windy but if you want to be in the sea and on the beach away from everyone and aren't worried about pure aesthetics then this is a great place