We were planning on taking the train. Easy on and off to get to the hotel and no issues with our carry-ons.
But the price of the roundtrip JetBlue is amazing.
The thing that I'm worried about is if we fly down, we'd most likely have to ship the stuff back.
FedEx and UPS do not ship on Sundays. So even if you make it to one of their locations on Sunday to ship your coral/goodies home, they won't leave that center until Monday evening for an arrival on Tuesday.
You would need a 48hr heat pack (minimum).
I'm going to do some searching on the MACNA threads from last time around. There were a bunch of discussions about bringing corals on the planes.