Danno,
You do not need to take off your rudders to trailer such a short distance. For trailering long distances, it is a matter of preference. Rick and I NEVER take off our rudders and have never seen any ill effects. We secure them in the "up" position. Other people ALWAYS take off their rudders.

All this is assuming that you are trailering your boat facing forward. Some people like to trailer their boat backwards, in which case you would always take off the rudders for anything farther than the 1 mile to your beach.