While watching this great video this morning about building a rock-skipping robot, I learned there’s actually a pretty tried and tested method for getting the most skips from a rock:

- Angle the rock 20 degrees upward in your hand. This angle creates a ramp on the surface of the water as the rock hits it which the rock then rides upward to effectively skip.
- Throw the rock at a 20 degree angle downward. This angle gives enough downward momentum that the rock dents the surface tension of the water to create the ramp, but not so much that it pierces the water.
- Spin the rock to give it rotational stability. Without rotation, the rock is more likely to flip end-over-end on hitting the water.
- As long as the bottom of the rock is flat, the rest of its shape doesn’t matter too much. As far as weight, it should be light enough that you can give it a good spin.
Armed with this knowledge, I’m gonna have to take my family up to the nearest lake or pond soon and find some rocks to skip …