We did parasailing in Catalina. Wasn't cheap, if you wait until 2-3oclock they dropped the price for us a little.
In Ensenada, take the busses from the port to the Main Street area. $3 round trip. From there you can book anything that you could have via Carnival for 1/2 the price. We did the blow hole, and let the kids hold a Black Panther at the jungle restaurant there. Wasn't super exciting, but for 4 of us it was maybe $60. Other groups liked the horseback riding.