Oysters used to be shipped in sawdust to Chicago, via the Erie Canal, from the East Coast. I've seen newspaper ads from the turn of the century touting that such oysters would keep for weeks. Maybe that's true. It seems likely, however, that every second out of the water is a second's worth of lost oyster flavor.
In Australia last November, I had a chance to visit the Pure Coffin Bay Oyster processing facility in South Australia. It was enlightening. My guess is that people on both coasts are probably very familiar with oyster farming strategies; for me, it was a new experience.