This 4 day cruise to Catalina Island and Ensenada was amazing. Cruises are what you make of it, and we decided to have a great time and take advantage of everything. Embarkation in San Diego was very easy and quick. The safety drill was painless, as Carnival no longer requires you to wear your life vest or pack in like sardines. The dining room service was exceptional as usual, the food was delicious and plentiful (try the West Indian Pumpkin Soup... I wasn't sure I'd like it as much as other cruisers do but wow!) The only major annoyance of Carnival is the pushiness of servers near the pool to buy drinks from their trays (which are less potent than ones ordered at the bar).
Catalina Island was beautiful and a nice beach town. We took the $4 trolley up to the Botanical Gardens which were kind of nice and then went down to the beach. Once Descanso Beach is finished with construction, it will be beautiful. The town itself was very cute and a nice relaxing day. Kayaking may be a nice option here. People said the glass bottom boat was pointless.
Ensenada Mexico was rich in history, but not an amazing port. We still had a great time, but vendors are very pushy, and the town is a little dirty. I hear the port won't be a stop anymore, which is probably a good idea. Our kayaking tour may have been awesome to the coves and hideaways, but it was cancelled due to rough seas.