This achievement is actually pretty easy if you use the Windows Button method. Start a single player game of Salvo mode. Choose five targets keep track of where you hit a ship and if you haven’t hit five separate ships hit the Windows Button on your phone. As long as you hit the button before the AI takes its turn, when you go back into the game you should be back to your first turn before you made your choices. Simply keep repeating this process over and over until you have found each ship. You can tell which ships you have hit because the silhouettes of them in the bottom left of the screen will flash red.