Q. 1. Does the Catholic Church practice, anywhere in the world, the Sacrament of Baptism by submersion in the Roman Latin Rite?
A. 1. First, to explain the meaning of submersion. Where Baptism is practiced by submersion, the candidate is completely submerged under the water. No part of his body is visible. Where Baptism is practiced by immersion, the person is simply placed in the water.
The Catechism of the Catholic Church, # 1239, states: "Baptism is performed in the most expressive way by triple immersion in the baptismal water. However, from ancient times it has also been able to be conferred by pouring the water three times over the candidate's head." In other words, acceptable practices in the Catholic Church are when the person is immersed (not the entire body) three times in the water or water is poured three times over the person's head.
In the days of the early Church the Sacrament of Baptism was only administered by immersion. This was changed to only pouring in 1311 A.D.
When Jesus was baptised, He was immersed in the water by Saint John the Baptist.
Some of the Eastern Rites that are in communion with Rome (unity with the Pope), such as the Greek Catholic Church, the Melchite Catholic Church, etc... they practice immersion as their regular form of baptism.