to pay?

It sounds as if someone here responding to the initial problem, the not performing a service billed for, is oddly defensive for the person billing for the service that was not performed. As the performer was questioned and even when showed the problem of what was done (or not) chose to stand firm without indicating he might have done the wrong boat, thereby choosing not to provide the service expected by the customer. a professional will always go back with the customer to verify, and if the job was truly unsatisfactory,would correct the problem by doing what he was expecting to be paid for. If the job was the status quo for that particular diver, and he thought his work was up to standard,I would have hired another pro to verify. They are competitive,and maybe this guy goes on doing business like this and intimidating customers (when and if challenged). The best thing in hindsight would have been to keep this quiet while consulting other boatowners who may have used him in the past. There are customers who never look at work performed. Good thing you found the rope, I'd ask the harbormaster to observe comings and goings of the diver, and if anyone else has ever mentioned a problem before. It could ring a bell. Helen