Call up Alvin at
Native Sons and setup your dives with them... Good shop, loved the people, and they have a 1 800 number to call so no phone charges! With Carnival, they try and capture you at their docks and want nothing more than for you to stay at Mahogany Bay. Taxi's that come up to ferry people out pay a fee (my understanding) so we walked to the outside gate and had a taxi waiting for us (good to have a contact at times) which took us to Native Sons... The ride is not that long by taxi and remember, you are paying for the return trip as well so when they say 40.00, its round trip. They should not ask for payment up front and if so, only give half. They will pick you up and then return you to the boat.
These dive shops know exactly how these cruise ships work... Schedule of arrival in case your late or early, and departure time... Personally, I will not dive with the boats "excursion" as they tend to take all divers to the same spot time and again. I like this as it keeps those who dive 2-3 times a year from destroying the reef system...
Again, my suggestion is to get out of Mahogany Bay and into the West End area from the get go... See how the people really live and buy a gift from the locals in the West End...
I have been to Roatan several times and once via Carnival... Since Carnival changed our port of call from Belize to the Caymans after we were at sea, they lost my business... not that I was a big cruise fan anyway... Oh, speaking of which, if the cruise blows off Roatan or time in port in cut way down; Native Sons will not charge you...
I am sure others will chime in with other shops but this was my one experience on Roatan off a cruise ship... otherwise I stay at CocoView and I can recommend them as well as an AI...!
Hope your trip fairs well, lee