Cages, traps and rings, oh my!
Promar and Danielson both make collapsible crab pots that make stowage easy. I have both the Danielson folding crab trap and one of the many Promar folding traps, the TR-102. The Danielson pot is 24x24x12 and is made of vinyl coated steel wire. This is one of the most popular recreational crab pots you'll find in the PacNW. They are very inexpensive and I picked mine all up while on sale for about $15 each. Each side offers a swinging door to trap crab. Each side clips into place, and to fold, just unclip two opposing sides, fold in, and the trap will collapse on itself. It is very easy to store several of these pots on the back of your kayak.
The Promar TR-102 is slightly larger at 32x24x11. It features a steel frame with nylon webbing. My favorite feature of this Promar trap is that it is center hinging. This is very easy to operate with 3 clips across the top to set the trap up. When it comes time to sort your catch, just set the trap across your lap, unhook the 3 clips, and let the trap open up and get to sorting! Promar now also has a 32" round folding crab pot. This one is spring loaded, and features the same nylon webbing, and 4 entrance funnels. The top features a drawstring entrance to make getting in and out of the pot for sorting an easy task.
Crab rings are also an option. They are not a trap, but mostly a "welcome mat" with bait in the center. Crab rings require more work as you have to constantly check them. They cannot trap crab, so its easy for them to grab a bite from your bait and crawl away. They're a good option for crabbing, but not something I like to use.
Rope, Buoys, and Accessories
With your crab pots in hand, you now need rope to get them back out of the water. I prefer to use lead-core rope. The lead gives the rope just enough weight to sink slowly into the water. This keeps your slack from floating on the surface of the water where it can entangle power boats. This is a great way to make enemies on the water. At 5/16" diameter, the leaded rope is very easy to handle while pulling up your pots, while standard poly rope I've found gets very slippery when wet. How much rope to you need? I like to suggest about 20' more rope than the depth you'll be crabbing in. With tides and currents, 100' of rope is good for about 80' water depth. If you find yourself crabbing a variety of depths, you can easily use clips and several sections of 50' rope to adjust to your needs. If most of your line is leaded, you can get away with using a less expensive poly rope for your top sections.
Speaking of your top section, you'll need a buoy to keep your rope afloat. I know we just talked about keeping the rope submerged, but we do need to be able to pull things up. Check your regulations to see if your crab buoy needs to meet specific guidelines. In Oregon, there is no such law, but in Washington, crab buoys must be red/white. Styrofoam floats take less space than plastic bottles, so leave your old bleach bottle in the garage. It's also useful to mark your buoy with your name to help ID it. I also include my license number.
On top of my pots you'll notice the blue harnesses. These help make sure your pot stays level when you're pulling up your crab. They are not a necessary item, but I do find things to be easier with them. I also leave these on my pots when I have them folded up for storage.
If you find yourself crabbing in a heavy current, you'll want to add extra weight to your pots. Most of the time their weight is good enough on their own, but I find a little bit more piece of mind by strapping on a pair of 20oz lead weights to each pot. It may not seem like a lot, but that's enough to double the weight of most collapsible traps, and make them stick to the bottom when you need them to the most.
Scotty Mounts also makes a great device called the Trap Ease. The Trap Ease fits most common Scotty bases, and is sold with their standard deck mount. This gives you just a bit more leverage to make pulling pots that much easier. If you find yourself crabbing a lot, then you'll probably want one of these. The Trap Ease is also great for pulling up anchor if you're fishing deep moving water like I often do. While I don't have one just yet, I'll be on my boat soon.
Finally you'll need a crab gauge. These will help you quickly determine the keepers from the throw backs. Most gauges also have cut outs for sizing clams, and illustrations to help you ID male keepers from a throw back female.
Of Bags and Bait
There are as many bait options as there are for trap setups. Old herring left over from salmon fishing works great, as do carcasses of salmon, rockfish or tune. Some crabbers swear by 9 Lives cat food. Others by Friskies. Albacore tuna bellies are loved by some. Lastly chicken is well known to catch crab as well. I usually use chicken or fish parts. The advantage of chicken is that it does not attract sea lions and seals, which will destroy your crab pot to steal your bait. Bait should be put in a container inside the trap with either a bait cage or bait bag. Cages are wire or plastic mesh and can become bulky in a kayak. Bait bags are much easier to use because they can be left inside the pots when they're folded. The Danielson pots do not include a bait bag or cage, while the Promar pots do include a nylon mesh bait bag.
Putting it all to use
Ok, time to start crabbing. A fish finder and GPS will be very useful. They'll help you find a nice sandy bottom where you'll find Dungeness. The fish finder will also help you know the depth that you're at so you're sure to have enough rope. You'll want the GPS to mark your spot to make finding your pot easier. It's amazing how much things can move with tides and currents, and the GPS will usually get you within a few yards of your buoy. If you're dropping more than one pot, just paddle off about 50 yards and drop the next.
I like to give the pots at least a 2 hour soak, if not more. There are a couple places I know on the Oregon Coast that will have you limiting out in less time, but I like to give myself more time to fish while the pots are sitting. If I have the time, I'll let them sit a whole tide cycle. Especially in bays and estuaries this long soak is important as the crab move in and out in time with the tides. If you're in more open water this is not as important.
Once it's time to retrieve, paddle back to your buoy and start pulling up the line. I usually toss the line off the opposite side of my kayak, though I would rather avoid doing so. If you have a Scotty Trap Ease, grab your buoy and run your line over the pulley. Pull the pot over the side of the kayak over your lap and begin sorting. Often times crab gets piled into my crate, but a burlap sack works just as well. Then just throw them in your hull if you'd like. Grabbing crab by the back legs will help avoid the pinch.
To sum it all up, here's one of my PacNW brethren, Bryce Molenkamp from NW Kayak Anglers demonstrating much of what I've said!