Take a rectangular sheet of paper
Fold it in half from top to bottom
Fold it in half again from left to right
Open it back up
Bring the top corners down to the center fold
Fold the bottom flap up on one side
Turn it over and fold the other bottom flap up
Open the folded triangle from the bottom center
Flatten it into a square shape
Fold the bottom edge of the square up on one side
Turn it over and fold the other bottom edge up
Open the triangle from the bottom center again
Flatten it into a smaller square shape
Hold the two top points and pull them apart
Shape the paper into a boat