The only place i know of that has coral/reef close to the shore if to the western most end of the isle, Clifton Peir. They are currently developing this area into a sort of park. Security keeps moving me on when i try to dive there.
To the West End of the North coast is Compass Point. If you have a sea kayak of other small boat you can get enough of a view of the immediately surrounding sea to pick the Darker Coral patches. But, they are few and far between, small and very shallow.
With out a boat, you'd be looking for a needle in a hay stack! With one you'd be best snorkelling or paddling the half mile to the drop off where there is lots to see and enjoy!
Worth a mention is that the North coast is VERY busy with everything from Cruise Ships to jet skis! In my experience your inflatable dive flag invites all the merry fools to come and investigate!
I've never stayed at Land Shark, so can't comment first hand. It's supposed to be a bit rough and ready. Orange hill has a better rep, but it's probly more expensive for that. O.H.'s closer to Stuart's though.
Frankly, if you're here for a week or more, you could do worse than grabbing a puddle jumper to Govenor's Harbour ($150). Head to the Atlantic side (East) and throw you self in off Banks Road (the coast sand track) Coral Heads from about 50 yds of shore. Can get a wee bit choppy though.
Hope this helps! if you want up to date prices or pics of Land Shark or Orange Hill, PM me and i'll forward. They're within a couple of miles from here.
Good Luck!