"Crab boils date back centuries on the Chesapeake Bay," write the people who are selling "crab boil" events—for $67—in New York City. These people are frauds and liars, selling ersatz "authenticity," pretentious unpretentiousness, a twee New York fabrication that has nothing to do with the tradition it wishes to evoke.
There is no such thing as a Chesapeake "crab boil" and there never has been. That phrase is not uttered between the Mason-Dixon Line and the Potomac River. Blue crabs from the Chesapeake Bay are steamed, never boiled. You put them in a big pot (a crab pot), with a rack inside to elevate them over some boiling water and/or vinegar and/or beer, and you steam them. (The crab pot you cook in is not the crab pot you trap crabs in.)
The authentic folk term for eating steamed crabs, Maryland-style, is "eating crabs."