Four men were fishing in a boat on the lake.

The boat turned over and all four men sank to the bottom of the lake.

And yet, Not one Single man got wet.

How is this possible ?

There’s a bridge across the Rio Grande connecting Mexico and the US.
The Americans have a watchtower on the Mexican side. There is a guard who has strict orders to shoot anyone leaving Mexico and turn back anyone trying to enter Mexico without a pass.
The sentry comes out every 3 minutes with a rifle and a megaphone to check the bridge and carry out his orders.
It takes exactly 6 minutes to cross the bridge.
There is no check on the US side.
How does cunning Mrs Gonzales manage to go across to the US without getting shot ?