Stay away from the prow, sit facing out and keep an eye on any oddness in the water. The advice for the lower decks is in the face and important unless the sole intention of your cruise holiday in the Sunderbans is to become tiger lunch. The Royal Bengals of this mangrove morass, bisected by rivers and estuaries, are the world’s sole swimming stripes and they are known to knock over fisherman from his boat with force equivalent of a 200-kg torpedo. Unsuspecting vacationers are no exception.