My sister recently had an experience with exploding sodas that were left out on her carport. It was amazing! There was scrapnel everywhere. Some busted along the seams...some blew the bottom out and took off like a rocket.
Since the cargo hold of an aircraft can possibly get very cold, I wouldn't take the chance. Buy it before you board. Plus, you don't have to haul around that extra weight or leave clothes behind you might want to bring.
I would definately buy it at the port city before boarding the ship, I'm sure a cab driver would be happy to make a stop at a gas station along the way so you could pick up something. I have had other liquids burst in my luggage so I'm very weary about packing anything that might burst in my checked luggage, I don't want to have to deal with that mess again. If soda cans burst in your luggage no amount of wrapping in plastic bags would contain the mess because, as mentioned, they can create alot of sharp metal schrapnal which would slice right thru the plastic. I have had soda freeze and burst in my garage and it was not fun cleaning up.
I flew out of salt lake city with three cases of bud. I wrapped them in a towel and then put them in a large garbage sack , just in case they blew. Never had any blow up or so much as bulge. Buying a beer can be very expensive on a ship. I figured it saved us a 200.00$ or so. I believe beer on the ship is about 3.00$ a can. enjoy your cruise