Here's what we do...
We bring along a large cooler left in our truck for when we get back to the launch. We transfer all bugs/crabs to the cooler along with all the seaweed we brought back to help keep them alive, enough to fill a regular plastic grocery bag will do. If you bring seawater to put in the cooler make sure it's not more than a 1/4" deep, just enough to keep the seaweed moist.
The crabs we'll cook alive in a big pot of boiling water. They don't seem to stay alive well in the cooler. After cooking we put the whole crabs in 2.5 gallon zip storage bags, collecting a bunch, for a "crab meat pulling day".
The bugs can stay alive for as many as 3 days, but we tend to them ASAP. Whenever that is, we get another huge pot boiling on the stove, then start the somewhat cruel process. While alive curl their tail under their body, gripping the body in one hand, the wrapped tail with the other, then twist in opposite directions. Usually at about 180 degrees the two will separate with a slight pull. If gripped firmly you won't get much resistance from the bug, but it's basically alive, hence we drop the body into the boiling water ASAP to end it's misery.
We clip all sharp points on the raw tail and bag what we want for the vacuum sealer. Small ones, usually 2 in a bag with the softer underside facing each other. Large tails we can split for a meal, usually one per bag. We're not gluttons and savor our lobster eating experiences. Plus, we don't routinely score the huge amounts some people do.
Down the road, we usually combine ""crab meat pulling day" with "lobster body meat pulling day". Some of this bug meat may be slightly stronger in flavor than the sweet, sweet tail. We use this meat for lobster enchiladas or a lobster pasta. The crab we just devour with butter. When you've got a mess of crabs and you're willing to wait until all the meat is removed before eating, you get quite a worthwhile and tasty reward
