If you will already be in the MK, just take the boat which is right outside the entrance to the MK. It takes about 20 minutes (if the boat is there). I would allow at least 45 min- 1 hour just to be on the safe side so that if you have to wait for a boat to come, you have more than enough time. When, you are done, just head back to the MK on the boat. That is the quickest way.