I dive under the water just in time! The Martian and killing every human they see!

Any large groups are vapourised with heat rays. Individuals are picked up to have their blood sucked later. Everything else explodes or burns under those rays. The water is boiling in places. I can't stay under any longer!

I should be hidden by the smoke and steam for a while. Should I go back to the shore and hide in ruined buildings? Or should I get in that little boat and travel by river? But what if the tripods are following the other boats? Or do something else?