Thanks for the tip on Umicoza. We visited Ishigaki and stayed at Hotel Patina down by the Ferry port. The hotel is an excellent budget hotel. I went to a tour operator at the Ferry port who spoke english. She said that she could make arrangements for me for diving either with a dive company near the Ferry, or with Umicoza. She suggested Umicoza because their staff spoke english. Having heard about Umicoza from you that's who I chose, and I didn't have any regrets. They came by in a Van and picked up both myself and my wife. They dropped off my wife at a village at Kabira bay before the dive/s and picked her up after (all with no extra charge).
The dives were fantastic. Lots of life on the reefs surrounding Ishigaki that I don't get to see diving in the Pacific Northwest. The entire Umicoza staff that I met spoke english. Harvey a Malaysian and his japanese wife run the dive shop and boat and both spoke english, as did Ako one of the dive instructors. We dove Hanagoi Reef on our first dive and another reef nicknamed Mash 2 (shaped like a large mushroom) on our 2nd dive. As would be expected on a reef dive there was an abundance of colourful fish, many interesting varieties of coral, cuttle fish, pipe fish, sea snakes, etc.
I also stayed on Zamami island (part of the Kerama islands) at Pension Takatsuki and used their dive services. The dives there definitely were not as good. I've got the feeling that because I was their only dive customer that they may not have taken me to their best dive sites. We went to a dive site just off Ama beach for our first dive and then to butso butso sango for the second dive. Octo, lion fish, and white tip reef sharks were the highlights.