The day before, thaw the shrimp in the refrigerator.Peel them, leaving the last ring. Drain the shrimp and remove excess moisture with paper towels. Make small cuts on the curved and inner part of the shrimp to straighten them.Tempura batter:In a bowl, combine the flour, cornstarch, salt, and coconut, and form a well in the center.Gradually add the water, mixing with a whisk.Add the egg and mix again.Take the shrimp by the tail and dip them in the tempura batter.Deep-fry in a deep fryer for about 2 minutes at 350 F (180 C) or until they are golden brown.Drain on paper towels and serve immediately.