Because if they fell forwards they’d still be in the boat.
I'm not hungry exactly, but I could still use a light snack".
Spring water
Because they are two tired.
Mine would have to be Why did sally fall out of the tree? Because she had no arms. Knock knock. Who's there? Not sally.
If they jumped forwards, they would still be on the boat! Sorry.
A sink.
Because is they fell forward they'd land in the boat.