Otter, I would think the diesel
fuel is the least of their worries, considering the vast amount of tonnage sunk off that coast during WW2 which is STILL leaking
fuel. In the 60's it used to be normal to go to the beach and use "tar remover" to get the tar balls off, coming from the same
fuel.
Allowing diving or recovery IN THE INLET during daylight hours would seem far more dangerous, as traffic would no doubt be coming through with no idea the inlet was closed and then, where do they go? Not a good thing. So yes, I can see their logic, limited opportunity, least danger.
The boat? If it is like many other inlets, the wreck would be pulled out with the outbound tide and rapidly go into deeper water outside of the inlet. Might be more appropriate to use a RIB with sonar, even a
fishfinder, to locate the wreck.
Really, the authorities there are probably more concerned with safety, for traffic and for divers, than anything else. And as long as that wreck doesn't obstruct navigation--they're not going to get all hot and bothered about 300 gallons of
fuel.