Since it is still summer, there is still a need for picking delicious watermelons. Below is a “mostly” scientific approach to picking the best watermelons. It doesn’t involve “tapping”. Some people are good at tapping on watermelons, but I find tapping takes more skill. (Apparently bigger vibrations mean a thinner peel and more water in the watermelon.)
The method I use involves observing four things:
1) The watermelon should be heavy for its size. This shows that it is has a lot of water in it.
2) It should have a good size “yellow/white area”. The yellow/white area is where it has been sitting on the ground and the sun didn’t hit it. Why on the ground? Because it got juicy and heavy as it ripened.
3) It should have a curly stem. Watermelons grow on vines and as they ripen they grow curlier. This feature may be hard or impossible to see because the farmers often cut it short.
4) The bottom “tail-part” should be small. This is the end where the flower comes out. As the watermelon grows the flower wilts. Smaller means that less energy is spent for the flower and more to the fruit.
Have fun and enjoy!