I think the simplest solution is to require a permit. Check in at the harbormaster's office, pay $10/day for a permit, and post that in your window. No/outdated permit = citation. Low level citations could be a minimum wage part time employee's task. Ideally, the permitting revenue pays for a used whaler and a few of labor per week. These "marine meter maids" become the eyes of law enforcement, who get involved after "X" permit violations. One advantage to this is it will illuminate the demand for the anchorage. If no one is asking for permits, there's no need to limit their duration. If the phone is ringing off the hook in July and August, you have a 2 week max. If you quantify demand, you can modulate the restrictions appropriately less onerously.
One angle to this that hasn't really been covered is what's best for the town and the local merchants. They want money spending tourists to come, spend money, and then make room for more tourists to come and spend more money. Ultimately that is what's best for the town, and that's what the town's leaders should be trying to achieve, not what's best for boaters. Waterfront property is a limited resource and a revenue generator for towns. They have a right, if not a duty, to maximize the revenue that can be generated (especially from non-locals!). As was once said by a great statesman: "The needs of the many, outweigh the needs of the few" Unfortunately, boaters will always be "the few"
(WARNING....POSSIBLE TOS VIOLATION AHEAD.....)
I think one of the things that should be avoided at ALL COSTS, is to have laws intended for one thing, to be used for another thing. For example: There was a problem of people not having safety equipment so rules were created that says everyone has to have an anchor, horn etc. Now there is a problem with indigent people using resources unfairly, idyllic locations becoming dumping grounds, and waste pollution issues. It would be, in my mind, a HUGE over reach of government to apply the safety rules, to solve the crowded anchorages problem. I think approaches like that create ill will between residents and government, and show a sense of laziness and apathy by municipalities. Laws should be applied as they were originally intended.