1. Black Diamond watermelon: It is characterized by fewer seeds, crispy and juicy flesh, and relatively high yield. The flesh of this type of watermelon has a more delicate texture and is not easily hollowed out due to its high sugar flavor.
2. Black Beauty Watermelon: This watermelon has a black rind and an oval appearance. It is usually small in size, but the flesh is sweeter and more nutritious, and it is stored for a longer period of time. The flesh of the Black Beauty watermelon has a tender and juicy texture, and is more resistant to storage and transportation because of its generally long oval shape.
In summary, Black Diamond watermelon and Black Beauty watermelon have their own characteristics in terms of taste and appearance. Which one is tastier may need to be judged based on differences in personal taste and preference.