Baptism is an important ritual. It is a conscious decision you personally make. You choose to get baptized, either through a complete immersion in water or when water is poured on your head three times. Baptism is your second birth. Your biological birth you had no say in. But your second birth is a decision you make. You choose to get baptized.
You do it for yourself but you also do it for others. You are propagating the message that there is a decision to be made.
Forget Jesus walking on water, water itself is miracle.