I PERSONALLY  believe no one other than owners and  designated dealers for repair or delivery of owners/associate members  boats should use the ramps.  It is not Just the ramp use that is a problem. Parking of the vehicles and trailers in our lots and on our streets  and tying up ramp usage in peak times  that inconvenience our owners  is a part of the problem, as well as after hours misuse, though even our owners could be at fault here.. 

The larger issue is monitoring all of this, not a fee collection.

  My PERSONAL thought is that A coded gate is probably the most reasonable, though nothing is totally without flaws, but it would be a good start. These coded gates are used throughout all the county in communities with a fair amount of success.  Needs no personnel at the site and the codes can even be changed easily to keep the code from being "borrowed" all season by dishonest folks.  Owners using the gate can just keep on top of the code changes and give a temporary code to their dealer or repair person.   Small inconvenience for security.  Could even help with the "night raiders"

disclaimer: I am a former chair of the Marine Activities Committee that studied this issue over and over and over.