Have you ever thought about taking prawn traps?
The crabbing is a little sparse in the area, especially in August. You can get a few, but you really need to know where. Your best bet will be in Tahsis Inlet (farther from town the better, down between the Pile Dolphin and the south end of Strange Island, probably your best bet), north end of Espinosa Inlet (south of the tribal area), and Rolling Roadstead (just west of the base of Leading Hill, around the rocks). Other than that… I have had some luck offshore, but you are more apt to catch a shark, starfish, or an octopus, then a crab!
If you really want to try, remember that area has the largest population of sea otters on the WCVI and they love crab. A sea otter can dive up to approximately 60 feet, so you have to drop the pots below that depth, or get in any area free of otters. The otters keep the adult crabs pretty much in check, but if you want to see something really amazing drop a prawn trap in Nuchatlitz (by Lord Island) and let it soak for 2 or 3 hours. When you pull it… it will be full of baby Dungeness crab!
Make sure you use fresh bait and you have to get a lot of scent out. Lots of salmon guts are good, but that will also attract the sharks, and a green light will help immensely! And, with all this information, you might get a couple of "keepers", but will more than likely get a couple of small "females", which you will get to throw back!