Here's more info than you may want, but thats my nature...
Before I get into the nitty-gritty, keep in mind that places like Hammond and Tillamook can have very strong Outgoing tidal flows, and/or strong winds, which make getting back very slow, perhaps very difficult, for a driftboat. And if your motor fails, it is long row back. I've only crabbed Netarts a few times, once in a driftboat, and it might be a place to try - just watch the outgoing tide if you are anywhere near the mouth (which you do not need to be). Also watch for the sand bars (as in every tidal area). Tillamook is a great place to crab, but the places I like best have strong flows on the outgoing. I've not tried very much around the Coast Guard Hole, and never in the Ghost Hole, but as long as you are out of the Salmon fishing areas, they might be worth a try.
I crab Yaquina Bay about 90% of my crabbing trips, so I'll use that as a reference. It is normally very easy for a driftboat.
Following are my general guidelines, although I make minor changes depending on the time of day, difference in tidal change, etc. Here is how I do it...
Tides: Pick the slack tide that works out best for you. Given a choice, I pick a High slack, but for me, it is not worth getting up at 3:00AM to go crabbing. I begin crabbing two hours before the slack tide, and plan on one hour after the change (sometimes when there is only a 4-ft differnce between the ebb and flood, you can go longer; a 9-ft change maybe less.)
Depth: My rope's actual length varies between 40-45 ft, so I crab in 30 ft or less of water. Because of the Commercial boats coming and going, I stay out of the main channel.
Traps: I now use Danielson's square traps almost exclusively. I have used rings and pots, but find the Danielson's retain the crabs much better than rings (rings have to be pulled fast to keep the crabs from swimming out, especially the big, hard shelled ones!). The Danielson's are much lighter, and much less expensive, than pots. I use 3/8 yellow poly(?) rope for the harness, and for the rope to the float (does not soak up water, yet is big enough to grip well). If you do not want to purchase the "regular" bullet-shaped floats, you can make from bleach bottles, etc. Just be sure the lid is taped or glued shut. Don't forget to secure the knots well.
Bait: Bait cages are helpful because the crabs can not drag your bait away. They are also good for deterring the Sea lions in Yaqina (although for the past 2-3 years, I've not had a problem with Sea Lions tearing up my traps, but I'm sure they will still go after bait they can easily get to). Shad and Salmon carcasses are very good bait, the fresher the better. Other fish carcasses work good too, and you can dumpster-dive at the fish cleaning station at the South Beach launch(may or may not find any bait). Chicken parts will work, look for the 10 pound frozen bags, and some sort of scent can help. The Newport Marina Store usually has crab bait of one type or another (they are good for advice, and rentals too).
Laying Out and Picking Up the Traps: I attempt to lay the traps out in a straight line, in line with the current flow/channel. Put out the float first, and then when you are sure the rope is not tangled, drop the trap. Continue another 150 feet or more, and drop the next one, etc. After 15 minutes or more, you can start picking them up. To pick-up, first visualize how the trap and rope are lying in the water. You want to start at the float, and work your way to the trap, picking up the slack rope as you go. Sort your crabs in the trap, or on the floor, get your trap back down, and head for the next one (if your are so inclined, you can get a rhythm going, and will be able to pickup one trap and get it back down in time to pick up the next one, all without stopping).
Misc Tips: (1) Especially with a driftboat, a good boat operator is helpful. Ideally, they/you want to operate the boat so the rope is straight up and down to signifcantly lessen the effort the puller has to do. This is easier said than done. (2) When pulling, try to keep the rope from rubbing against the chine (this really adds to the resistance and effort necessary to get the trap up - think blisters and sore back). (3) Keep your rope, and others ropes, out of your prop. (4) If you run or drift over a rope, turn the motor off, or at least out of gear, until you drift off the rope. (5) Be sure you know how to handle crabs to prevent getting pinched, which can cause some noteworthy finger damage if the crab is big and mean, which the better ones are. (6) Have a bucket, ice chest, or something to put put crabs into. (7) Do not keep store them in a bucket of water (they live longer out of the water than they do in a bucket of water.) If you feel it is necessary to "refresh" them in salt water, try to do just one or two carbs at a time, otherwise, they will claw, pinch and crush each other). (8) I place the crabs upside-down in my bucket, to lessen the damage they do to one another. (9) A boat hook may be useful to snag the rope, and some folks use gloves to handle the rope and crabs. (10) Crabbing is fun - enjoy it.
Yaquina Bay - where to crab: for starters, after coming out of South Beach Basin, turn right and head up the Bay (remember the warning about sand bars). Look for the Red Channel marker just ahead, and you can start dropping your traps there, or go a little further up the Bay. If you stay about in line with the red channel markers/buoys, you will be in pretty good depth. Quality crabs can be had for a mile or so up the Bay. Another popular area is in the vicinity of the green LP tank, which is a distinctive landmark across the Bay.
Good luck.
