we made a cruise from ushuaia to rio in 2007. started in ushuaia to antarctic island and have storm 2 days, but this is normal between the atlantic and pacific. on the islands (elephant island, desception island, etc.) the weather was really good, cold but the sun was shining. we also cruised through the gerlachstreet. we saw a lot of whales, robes and thousand of pinguines. we needed for landing on the islands boots, because the tenderboats dont go straight to the land. we made our cruise end of feb and it was the last cruise for ships, because the winter was beginning. the greatest adventure were the icemountains. we were six days in antarctica and then go to falkland, also we had 2 days storm. hope you are not seasick, but the cruise is it worth.