watermelon mistery

[the1honeycomb]

I was excited when the watermelon seeds I purchased started growing and they grew exactly where I wanted them to. I have 8+ melons, then i realized that I don't know what kindof melons I have! the package doesn't say!!!1 they are now about the size of a small medicine ball, dark green and growing steady. Look healthy but how do I know when they are ready?!?!?
I am very excited this is the first time for me in many regards. This is exciting, and I will wait as long as I need any suggestions???

 

[catjac1975]

When you tap on them they sound hollow when they are ripe. They should smell sweet also.

 

[lesa]

The light colored spot on the bottom, where the melon sits on the ground- should be white.