We do all our crabbing in the Columbia River a few miles inland from the bar. I set out five pots between buoy 22 and buoy 20 in 40 - 50 feet of water. That puts us safely out of the channel although there is always current running one way of the other with the tide except at slack tide if there is no wind. Finding no wind this time of year isn't too likely so there always seems to be surface current.
We drop the pots about two hours before slack tide and then go closer to shore to anchor. Really though, I suspect we would get just as many crab by waiting until a half hour before slack to set the pots. My theory as told to me by a guy who should know is that the crab in the deeper water near the channel bury themselves in the sandy bottom until the current down there lets up, then they crawl around looking for food.
TV, movies or Yahtzee along with snacks and coffee fill the time while we wait. I have a ring trap that I drop over the side while anchored and check every 15 minutes or so. The choice to carry five pots is because that's how many will stack up safely on the deck (I use cinch straps to keep them stacked) and also because we are allowed three devices per person and there is usually two of us on board. So five pots and the ring keeps us legal. I also have a couple snare traps that we toss out with a fish pole if there are more than two of us aboard.
Like I said, there is always a little surface current but the floats are easy to spot at slack water. When the tide is running hard the floats will disappear under water so we like to start pulling the pots right at the end of a tide to make sure we get them before the tide turns and the water starts ripping. I prefer going out just before a high tide and the river can get nasty real quick on a strong ebb so we almost always pull the pots a little early. There are crab there at low tide too, but the water is saltier at high tide and there seems to be more crab in the pots.
The count for the TyBoo so far this year is 497 crab kept, cleaned and cooked. We have given away most of them and our friends really like us this time of year! They are very easy to give away. One big bunch of them went to the widow, son and grandkids of the late friend the TyBoo is named for. If we take friends or family out there with us then they get the entire catch to take home.
The total for the boat since I retired from work and bought the electric pot puller stands at 1492 which gets the cost of the puller down to about 80¢ per crab. When it gets down to four bits we can slow down a little.
Don't worry about us depleting the fishery - the average annual harvest for the Oregon commercial fleet has been 16 million pounds per year for the last 25 years according to ODFW. It is the #1 commercial fishery in Oregon. The larger legal size male crabs do not contribute significantly to the reproduction rate - like with most species it is dominated by the young guys - so leaving the smaller males and all the females in the water always replenishes the supply.
Long story, but I like talking about crabbing almost as much as I like catching the things.