Hollow stems and squash point to SVBs, though they usually leave prominent traces of their penetrations.

Moschata squash are considered to be "SVB resistant", perhaps for the same reason that watermelons are considered to be, but in my neck of the woods, that doesn't stop them. More stem to drill through, but they'll get it done.

Watermelons can die quickly unless there is little or no wilt disease pressure in the soil.

Man, if you only knew how many have died on me,

It's been quite moist.

Don't plant melons near this spot next year....or for 4 more years at least.

The spot I have picked out for next year is about 20 feet away, is that far enough?

Although there is a chance that you have SVB my suspicion is that your plants are suffering from Downy Mildew which is rampant now in the Mid-Atlantic Region. This fungal disease does not normally overwinter in this region so moving your melon crop location will not help to control it. Once it arrives you need an aggressive spray program or it will kill the plants in a few weeks of favorable weather(for fungal growth).

What would be the signs of it?