I have boated in waters where mooring balls can be reserved in advance and it works well. You reserve, get your ball number and tie up. This allows you to enjoy your day and sights along the way to your next spot without worry. There were always "check in" and "check out" times no different than a hotel. On occasion you may need to inform someone that you have a certain ball reserved. This was never a problem as the balls were well marked and the boat knew they were in the wrong and just trying to get away with something (same boaters who tie up to private mooring balls or overnight on National Park balls.)

Having some balls available for reservation and some first-come first served caters to all interests and styles of boating.