Choosing a good watermelon

Look at the "underbelly". That's the part the melon has been sitting on all this time as it matures. The color will range from pale green, to ivory, to yellowish, with the pale green being the least mature. Therefore, you will want a melon that has a dark yellow underbelly, because that means your melon has been allowed to ripen on the vine and will be sweeter and full of juice.