I’ve attended a couple LDS baptisms of some friends. The baptism is usually held in the chapel or a baptismal room…there’s the canidate and the person doing the baptism…and in the two I’ve attended there are two “witnesses” to insure a proper baptism occurs…the canidate has to be totally immersed…a good friend had to be dunked four times…the missionary baptizing him was small and my buddy was “bigger”…each time he went under his hand or foot came out of the water.
The person officiating raises his hand and states…"Having been commissioned of Jesus Christ, I baptize you in the name of the Father, and of the Son, and of the Holy Ghost. Amen” (D&C 20:73)…and the person is immersed…then after a change of clothes…they were confirmed.