Seaworld

Is it less expensive to do seaworld on your own rather than thru RCCL? How would you get from pier to seaworld if you did it on your own and what would be the costs?? How far is Seaworld from the pier?? Also--I have another question--How's the drinking water in Ensenada--is it something to be careful about (and always drink bottled) or is it safe to drink. how bout the ice?? thanks