Nobody cares about enforcement, or the quality of the NPT services. They care about the fee revenue. Enforcement costs would cut into that, so therefore it is a non-starter.

I personally think that there is likely some middle ground between an enforcement police state and the existing "tragedy of the commons", but there certainly doesn't seem to be any driver for the NPT to do anything about it. Maybe the major stakeholders (ie the charter co's) could muster some interest since it is the experience they are selling that is affected.

If I ran the NPT I would use a crowdsourced solution in consultation with other stakeholders like scuba operators, day sail charters, and charter operators. Start a website that does some "naming and shaming" - You could send photos with boatnames, time and date stamps, and the charter operators can see who the rule breakers are and perform whatever remedial action they deem appropriate.