I just got back from the Grand Lido Braco on Jan 2 it's about 30 min west of Dunn's river falls. The farther away from negril, montego bay and ocho rios the better the diving. Along the north coast is the better diving, mostly because the amount of tourists is reduced, meaning less people with resort courses with no bouancy control who kick the crap out of the reefs.
That being said we saw alot of nice coral but also A LOT of fish traps, meaning don't expect to see a lot of the bigger species of fish, you'll still see the odd sea turtle, rays etc. but anything that can be eaten is eaten.
If you are from North America you probably have not seen or grown accustomed to the level of poverty in Jamaica, everyone is trying to make a buck. The unemployment rate in Jamaica is around 50%, and the greatest trade is tourism with Bauxite a close second. With the latest down turn with the American economy over 650 people were laid off from the resorts along the north coast. So when you hear your bus drivers and taxi drivers giving you the sob story about mouths to feed it's most likely not just a line, they probably do need the money and are probably trying to work more than one job at the same time.