Thanks - we knew about these ferries, and talked to the Fiji people at the Scuba Show in Long Beach the other weekend. Nobody ever seems to be able to reach anyone in the Grace ferry office, so we haven't been able to find schedule, or even confirm the boat is in service right now. Greg (Fiji Diver here) has tried without success. Since we have to get from Matangi to the Koro Sun resort on Savusavu on a specific day, we figure our worst case option is chartering a boat between islands, but that's not our first choice. We'll have some time when we get to Matangi to figure out logistics - just trying to avoid any surprises up front...
I didn't but I googled a bit and found this for ya
By Ferry...