Be sure you always check what type of aircraft you'll need in the map room at the top of the page. Look for this section: "Maps and Starting Points for all RTMM Locations" You can see if they are paved surfaces, dirt, gravel, water, etc.
For water ones, you can plot a course using either a float plane or a boat. I love doing this, select a destination that is water. Then, using a good flight planner tool like Plan G, you can see the land and water route to get there. Now map out a plan where you can fly it. Take off and experience that aspect of RTMM in flight. Land at the destination. Now, switch to a watercraft you can get to in your FSX aircraft library and return to "Misty's Place" in a boat!!
It's so cool to experience that side as well. It looks completely different and is a new perspective you'll appreciate.
Have fun,
Brad