Back in 2010, there was a website that could have been a great help for burial at sea. It was called Track My Flush and was created for World Toilet Day. You could follow your flush from point of origin to its final destination using a Google Maps overlay showing your local sewerage system (from where I live in Midlothian it toook about three hours and went by a surprising route). Unfortunately Domestos stopped sponsoring it.

I prefer the idea of being used as cat litter though.