I talked with Floyd about getting Nitrox certified before a trip to Aruba. Floyd was really flexible and worked around my work schedule to do a class in time for my trip.
He did a great job teaching the class and was very knowledgeable. He made sure I understood everything before moving on to each new module.
I've been diving since the 80s and have worked as a dive master and would recommend Floyd and Waterworld if you are interested in getting certified.