Solo diving in Cayman is a no no. The government does not allow any solo diving and does not recognize licenses that permit solo diving. I am not sure if CITA (of which I a member) made the regulation or another agency but was confirmed about two minutes ago by the CITA Waterports Representative.
Unless you or the people you talked with can provide us with a reference to the specific rule or regulation, I would suggest you are providing and being told inaccurate information. I am ready to be corrected but I have seen this issue come up way too often.
Again dive ops may chose to adopt a practice for their own business regarding solo diving but I am tired of hearing the excuses that the government or CITA by regulation or guideline prohibits them from allowing solo divingt. When questioned on this I am always referred to CITA regulations or guidelines. When a review of the regulations reveal no such policy the answer then is always well that's what we do. So I think the accurate answer is most dive ops on GCM chose to prohibit solo diving which is fine but it is a choice not a mandate.
I make this point again and again because if it is a choice, a choice can be made on a shop by shop basis to change their policy. This is in fact the trend on other islands (BON and CUR come to mind) where shops are now recognizing the growing number of solo divers, the certifications that are now available and permitting solo diving by specific policy.
This reminds me of an argument many years ago I had with the owner of a dive op in the keys about the depth a jr. cert could dive. We booked a trip specifically telling the op we had a jr. cert. diver. When we arrived on the boat they would not let my son on because they said he could not dive below x even though his card said he could with an adult. We all ended up getting off the boat. The discussion continued with the owner in the shop. He pulled out a Padi manual. We quickly saw that he was misreading the manual as the depth limitation he was thinking of was for training, not for a certified diver, even for a jr. When the error was pointed out, his response was yeah your are correct but it is our shop policy so there.
The moral of the story at least with solo diving in GCM, if the policy is not one mandated or required in the CITA guidelines, shops are free to adopt their own policy which could be to ban it but they are also free to permit solo shore diving under circumstances they feel reasonable. That is a direction I would like to see more ops take.
Sorry for the digression from the main topic.