Here is some info on the Pass, but let me start by saying this can be a dangerous place if you dont know your way. the back side of the reefs can be productive but you can get caught if you are not careful.
the fist map is from
www.flashearth.com. you can really see the reefs and shallow areas. the channel in and out is safe to run but you have to be careful. it goes from 20ft to 1ft really fast. in the curve there is a deep hole then shallows up. when i get out of the hole I come off plane and idle to the reef i want to fish. I always use the island in the picture as a guide.
Second is from the Navionics web app. you can see the channels a bit better but you loose the detail of the reefs.
I use the standard mapping chip which is an Ariel photo it gives me enough detal without spending big bucks on a name brand chip.
good luck, and let me know if you have any questions.