Here's the first Navajo Winter watermelon that I've eaten, this year. It has a very thick rind (so it's probably a cross). Nevertheless, most of the rind is sweet and approximately the same texture as the inner fruit. It still has winter watermelon skin (in toughness). It tasted great! It was quite sweet and good. I definitely want to grow the seeds. The seeds were a pearlescent black (shinier than other black seeds I've saved before).
Notice how much of the rind I ate (what's left is the harder, non-sweet part of the rind):
Location: SW Idaho, USA
USDA hardiness zone: 6
Elevation: 2,260 feet Profile post