The cache is not at the posted coordinates. Guess you could go there by boat if you want but that won;t help you find this cache or solve the puzzle.
Use the information on this page to determine the location of the final. It should be a quick grab when you get there. The title sayes it all - just saying.
You are looking for a tucked in Magnetic Key Holder containing only a waterproof log. The log is best signed with a permanent marker - ball point and gel pens work. Pencils not so much. The coordinates have been averaged over 100 times to within 8'. Your result may vary so a generous hint is being provided.