Every guest who books a boat trip weeks in advance asks some version of the same question, usually near the end of the conversation and usually a little apologetically. What if the weather is bad? It is a fair question, and most operators answer it vaguely. This is our honest answer, written by people who cancel their own departures several times a year and would rather you knew the rules before you paid. If you are still choosing a route, start with our Lan Ha Bay overview.