How long can crickets swim?

I've had crickets in the basket of the pool that had been there for hours. Though they appear dead, I lay them out in the shade (out of the hot sun) and check them hourly. Little by little, they come back to life. It starts out with the antennae flinching a little. Then the legs start to work a little. Before long (a few hours at least) I can turn them loose in the garden. Blows my mind every time!