Man, you two have some beautiful melons. I'll have to pick your all's brain next spring for tips.
I'm good at growing vines but very few melons.
Who knows what next spring will bring...so I'll offer up a few of the techniques I use while you're interested:
1) It starts with great soil that is rich in organic matter, ph 6 or slightly higher, and as close to "No N-P-K required" as you can get it without synthetics. I do not feed during the growing process rather rely entirely on the nutrients that have been "preloaded" prior to planting.
2) I prefer to direct seed watermelon. It does not transplant well, IMO. I seed only when soil temps get reliably above 65 deg. F. Early cold stunted watermelon plants never recover to where they should have been, in my experience.
3) I use raised rows/hills to ensure good drainage and to aid holding the sun’s heat longer early in the season.
4) Watermelon needs 1 to 2 inches of water per week while young, but after fruit set the water needs to be considerably reduced. Dry weather produces the sweetest melon, but you can't always control that.