I've been in two situations where it's happened (both 2 stroke, which are
markedly easier to fix).

All of the advice I've seen here so far is pretty accurate.

We pulled the plugs, cranked the engine to get the water out and got
it running right away in both cases. One engine was a 100 HP Mercury
and the other was a 40 HP Scott A****er (dates it, yeah).

b.