I often visit Okinawa and have once gone GT fishing with a charter service through a fishing shop called Yosemiya. I believe the shop owns a boat which is captained by a guy named Hayashi Masami. Hayashi-san has his own company, Breeze Fishing Supply. If you do an internet search for "Breeze Fishing Supply", his site should come up. This particular service seems to specialize in fishing the areas off Naha and takes customers GT fishing at the Kerama islands, which is a small group of islands about 45 minutes by boat from Naha. The Ripple Fisher crew have often fished with Hayashi-san as have other well known fishermen and fisherwomen.
I have also met another captain, Uehara-san, who GT fishes the waters off a less remote set of small islands in the Katsuren area. However, I need to search through my things to find his contact information. I could not find his site with a simple internet search.
Given the remoteness of Ishigaki, it may offer better waters for a GT bite. I have never been there though. I think Fisherman is headquartered in Ishigaki, so it may be helpful to try and find out how Suzuki-san goes about GT fishing in that area.
