It doesn't matter if you are on a boat launch ramp and there are very few rocks around. It's the perfect thing to do to pass the time while you are waiting. Or making others wait for you.
It's the perfect thing to do when you are smack dab in the middle of the most beautiful scenery ever. Or if there are girls walking through the water in front of you, trying to get your attention (which they did, at their own risk, I should mention.)
Skipping rocks is the ultimate boy activity, even for older boys who have grown into dads. You don't have to talk, or you can if you want. You can let your mind wander as you perfect your fling or search for the ultimate rock, allowing deep thoughts to enter and epiphanies to occur. The meaning of life becomes clear, you are at perfect harmony with the universe.
Or, maybe you are just throwing rocks into water.