To find the correct coordinates for the cache, solve the Sudoku puzzle below. It rates a medium. Plug the missing letters into this to get the cache's location: N38 AB.CDE W104 FG.HIJ. There's a link below if you want to print out the puzzle to work on it. No need to cross any water or do anything dangerous. Keep a close eye out for muggles!
You can check your answers for this puzzle on Geochecker.com.