I blame tourists for a lot of damage. Here's the test: If the fish are friendly, you can bet the coral will be trampled and in a poor state. If the fish are timid the coral is generally pristine. Having said that, tourists only descend en masse on a very small fraction of the reef overall. As for needing to go a long way offshore, that's because for most of the reef's length the "true" reefs are quite a way off shore. There are, however, many areas of healthy reef available to tourists a short run from the mainland in many places.
That's not too far off the mark.
As kids growing up in FNQ in the '70s we enjoyed scaring tourists that enjoyed "reef-walking" (that's wandering around on top of the reef at low tide, picking up shells and stuff - and is generally discouraged now) a.k.a. "reef-destroying" by telling them stories about all the nasties out there waiting to wound, main or kill them:
- Stonefish (step on one and you'll regret your visit for the rest of your life)
- Stinging coral (lives up it it's name)
- Blue-ringed octopus (venomous)
- Cone shells (will fire a venomous dart at you even out of the water)
- Giant clams (waiting to grab you and hold you until the tide comes back in)
- Moray eels (don't stick your hand in that crevice there - you'll have no fingers left!)
"Hey, look! It's a (totally harmless black-tipped reef) SHARK!!" "Quick, get out of the water.. he's going to eat you!!"
Yep, those were the days!