Hi eedive,
I've been diving in Bligh Water, really worth to do it!! Almost on each dive we saw sharks (hammerheads, black tips) and huge schools of baracuda. But the best is to do it as a liveaboard. If you prefer a resort, you might try the West of Viti Levu. The barrier reef off its coast offers plenty of dive sites for divers of all levels. The abundance of soft and hard coral is amazing. We also saw frequently sharks and other big ones.
However, there are too many good places on Fiji, one trip is not enough! I will definitely go again (as soon as my budget allows

)
Sirius