Louisiana shrimp or crawfish boils are generally done in very large pots with very large baskets over propane burners. The pot is filled about 2/3 full of water, then a whole bunch of seasoning is added, either purchased or homemade. Once the water comes to a boil, small or chunked potatoes, cut garlic heads, and onions are added and cooked until about half done. Then, corn on the cob and andouille or another type of sausage are added, and cooked until almost done. Some people add whole mushrooms a few minutes after the corn and sausage go in, but we don't since DD left home. I love mushrooms, but cooked this way causes them to absorb copious amounts of the cooking liquid and they squish/squirt in your mouth. When everything is pretty much done, the shrimp or crawfish go in and are cooked until about half done, well unless you are my ex SIL, then gas is turned off and bags of ice or 2L soda bottles filled with water and frozen are added to the boil pot to cool off the liquid so that the seafood finishes cooking, but can stay in the pot to soak and be seasoned by the liquid. After 15-20 minutes at least, the ice bags/bottles are removed and the basket is pulled out slowly so you don't have a flood, then dumped out on a newspaper or brown paper lined table, and it's a free for all!
The reason I mentioned ex SIL is that he thinks the shrimp aren't done unless they are boiled for 15-20 minutes, then soaked. We quit buying seafood to take to his house after he ruined over $100 worth 20 years ago. Not sure what happened with him. His uncle's crawfish or shrimp boils always turned out great. In fact, the uncle gave Craig a couple of tips that improved his boils.
Maryland crab or shrimp boils really aren't. They are steamed, whether in a burlap bag lined pit dug on the beach or in the backyard, or done in a steamer pot with a fairly deep bottom part to hold the liquid, usually with a spigot for easy drainage when done, and a tall pot with holes in the bottom for the top, with a lid. Craig's family used a steamer pot with heavily salted water in the bottom, then layered the same vegetables as above, according to required cooking times, seasoning each layer with Old Bay, then used a propane burner to cook. Dumped on a table as above.
Small children had their shrimp, crawfish or crab cleaned for them until they were old enough to eat enough that an adult couldn't keep up with them and feed themselves. Adults were shown how to clean crawfish or crab 2 or 3 times at most, then you were on your own.