The answer is the first one
-to find where you are
-to find out where you are going
-to find the direction at which you are heading
-to find alternative routes to your set destination
The answer is - wavelength.
As the wave approaches the shore and it reaches shallow waters it's characteristics start to change. When the wavelength is half of the water depth than the bottom of the wave starts to drag on the ocean floor. As it starts to do this the wave starts to slow down at it bottom as it approaches the beach but the upper part of the wave maintains its initial speed. Because of this the wave becomes longer. Once it reaches the shore it crashes on it and falls apart.
Population is what they both have
It belongs to the lithosphere
