I know what you are thinking: "Cody, you can set a pot and catch crab." I know. I used to do that for a living. Unfortunately, that instilled a slight hatred of crab pots in me. Also, you need a boat, bait, line, buoy, an electric or hydraulic hauler if you are lucky, a depth sounder unless you are brave, and fuel to go set crab pots. I can throw on my wetsuit, weight belt, and fins and start crabbing right from the beach. If I'm feeling frisky, I could kayak somewhere, but the point is, it takes far fewer resources to freedive for crab than to set pots. I will still go out and set pots once in a while, though. I live a subsistence lifestyle, so going out and pulling up pots full of crab is useful when filling the freezer, but sometimes I only want a few. That is when I like to go dive for them.
Finding a dive site is pretty much the same process as setting pots. You need to find good crab mud. Most mudflats will hold crab, but there are always spots that are better than others. There are two major differences between finding a place to set pots and finding a dive site: depth and visibility. You can find all the crab you want, but it won't matter if you can't get to them. If you are setting pots, you can add another shot of line if it gets deeper. You can't add on extra lung capacity. There are exercises you can do to extend your breath-hold, but everyone has their limits.
Visibility is also essential. If you can't see very well, it will be much harder to find crab. The best visibility you can ask for is when you can see the bottom from the surface, so you only have to dive down when you see crab instead of diving to find crab. An incoming tide will usually give you better visibility as it brings in new water that hasn't mixed with the mudflat yet.
You don't need to carry much gear with you. I carry a crab measurer and a catch bag like this one. I like to keep my measurer on a wrist lanyard so I don't have to hold it the whole time and I can use two hands when grabbing crab. It can be a good idea to carry a speargun with you in case you run into a halibut, but I don't always bring one.
Most importantly, you should bring someone with you. Of course, having another diver in the water is best but at least have someone else with you. Typically when I dive, I will be the one in the water but will have someone in a boat or kayak following me around in case something goes wrong. The person in the boat will also be on picture duty to help document the experience.
GEAR LINKS