Peel the prawns if they have their shells. Cut down the back with scissors and separate the shell from the body. Hold the tail at the first joint and twist the shell off. Use a paring knife to remove the vein along the back of the prawn if necessary. Pat the prawns dry with paper towel and set aside.
Set up a standard breading station with three shallow dishes. Add the flour along with a good sprinkle of kosher salt to the first dish. Whisk together the eggs, water, and another pinch of kosher salt in the second dish. Combine the unsweetened coconut flakes, panko bread crumbs, and a pinch of kosher salt in the third dish and stir together.
To bread the prawns, hold them by the tail with one hand. Dip the prawns in the flour and shake off the excess. Then dip the prawn into the egg mixture, allowing the excess to drip off. Place the prawn in the coconut crumb mixture and use your other hand to press the crumbs onto the prawn. Gently lift the prawn up up and let the excess crumbs fall off. Place the coconut crusted prawns on a baking sheet and set aside. Repeat with the remaining prawns.
Heat the vegetable oil in a deep pot or skillet over medium high heat until it reaches 350° F. Carefully lower 5-6 prawns into the hot oil. Fry the prawns quickly for 4 to 5 minutes until well browned. Prawns cook quickly so they will be done by the time the breading is a deep, golden brown.
Use a slotted spoon to move the prawns around while they are frying. When the prawns are a deep, golden brown, lift them from the hot oil with a slotted spoon. Transfer to a paper towel lined baking sheet. Repeat with the remaining prawns. If desired, you can keep the prawns warm in a low oven until they are all cooked.
Serve the coconut prawns with the chili lime aioli and mango mojito dipping sauce on the side. Enjoy!