Remove green skin and the hard white part of Watermelon Rind. Cut up the white/lighter red part of the rind and place into a food processor. Process for a few seconds to make Watermelon Pulp.
Strain most of the Juice from Watermelon Pulp and set aside. Add 1 full cup of Watermelon Pulp to Pressure Cooker cooking pot. Add the rest of the ingredients.
Lock on Lid and Close Pressure Valve. Cook at High Pressure for 15 minutes. Allow all Pressure to release Naturally. Remove lid and simmer for 5 minutes. Remove a cup of Sauce from the cooking pot and set aside.
Remove membrane from back of Ribs and cut into sections. Add 1/4 cup of Watermelon Rind Juice and mix into Sauce. Add Baby Back Ribs to cooking pot and push into the Sauce.
Lock on Lid and Close Pressure Valve. Cook at High Pressure for 20 minutes. Allow Pressure to release naturally. Remove Ribs from Pressure Cooker cooking pot. Toss out liquid.
Place ribs on Cookie Sheet, bone side up. Brush with Watermelon Rind Sauce. Place under Broiler for 2 minutes, or until bubbly. Turn over Ribs and brush on more Watermelon Rind Sauce. Return to Broiler for another 2 minutes, or until bubbly.