How do you climb out of a river in Adventure mode?

Question

I deliberately entered a river in order to cross it. I used Alt+direction and my adventurer began swimming around the river. But now I can't climb out, on neither of the two shores.

Is there a different key combination to climb out?

Answer 1

Are you at least a novince swimmer? Because if you're not

Dabbling or untrained swimmers will start drowning immediately upon contact with water, and require a ramp or stairway to get out. If neither are accessible, they're done for. _{(Emphasis Mine)}

If you are, you should be able to alt-move above.

To get out, alt-move carefully against a shoreline and select the option to move above.

From: Dwarf Fortress Wiki: DF2010:Swimmer

Answer 2

It may well be that the river is in a 1 block high canyon, so you swim to the side but it's a (small) cliff rather than a shore. If that's the case then I think you're SOL.