Remove rinds and puree all watermelon flesh and juice in blender with all wet ingredients, until fruit is smooth (consistent in texture).
Add the pectin and blend quickly to evenly incorporate.
In a large pan simmer mixture for 5 min on medium-low. Increase temperature to medium-high heat till reaches a full boil (that can’t be stopped when stirring) and hold for a minute.
Slowly incorporate sugar.
Return to a full boiling and hold at hard boil (that can’t be stopped when stirring) for one minute. Makes about three 8 ounce jars.
Pour into small glass jars and lid. Be careful – the jam will be very hot!
Allow to cool to room temp and keep in refrigerator for up to two weeks.