Yeah, you have to watch out for those spur of the moment baptisms.
I see people babtized all the time at the Kern River here in CA. We'll be playing in the water at the park and they will be dunking person after person across the river. I've never heard anyone complain.
Like this one?
Acts 8:35-38
Then Philip opened his mouth, and began at the same scripture, and preached unto him Jesus. And as they went on their way, they came unto a certain water: and the eunuch said, See, here is water; what doth hinder me to be baptized? And Philip said, If thou believest with all thine heart, thou mayest. And he answered and said, I believe that Jesus Christ is the Son of God. And he commanded the chariot to stand still: and they went down both into the water, both Philip and the eunuch; and he baptized him.