For the syrup, cut the vanilla beans in half lengthwise. Scratch out the vanilla pulp with the back of a kitchen knife. Put 300 ml cold water, sugar, vanilla beans and vanilla pulp in a pot, bring to the boil and simmer over medium heat for 5-10 minutes.
Take it off the stove. Remove the vanilla pods, let the syrup cool down a little and pour it into a clean bottle.
For the margaritas, pour the juice of 1 lime onto a flat plate. On another plate generously add salt. Dip the edges of the glass first into the lime juice and then into the salt. Remove the glasses and allow the salt edges to dry.
Remove the seeds from the melon, remove the flesh from the hard skin and dice roughly. Place the melon pieces with the juice of 1 lime in a tall mixing bowl and blend finely with a hand blender. Then pour into a shaker.
Top up with Triple Sec, tequila and vanilla syrup and skake, shake, shake. Crushed ice and watermelon margarita into the glasses. If life gives you another 1 organic lime, then cut it into thin slices and decorate your glasses with it.