I don't think any town in Massachusetts has a residency restriction - isn't there a state law? I'm on the list in Marion and got removed, along with a bunch of other non-residents, and then got re-added when somebody complained that the removal was illegal.
I grew up in Marion - the harbors without waiting lists, don't have waiting lists because they're shallow and don't have any place for you to leave a
dinghy. But I could be misremembering, too.