Even ordinary ministers of Baptism are restricted in certain senses :
**Can. 862 **
“Except in a case of necessity, no one is permitted to confer baptism in the territory of another without the required permission, not even upon his own subjects.”
There are good reasons for this.
All Catholic Baptisms need to be registered…(even emergency Baptisms performed in a hospital should be registered in the territorial parish where the sacrament was administerd) Order is essential here and, for practical purposes,maintaining sacramental records would be all but impossible to maintain if everyone were going around baptizing … even ordinary ministers outside their territorial jurisdiction.
Canons 875-878 ( CHAPTER V.THE PROOF AND REGISTRATION OF THE CONFERRAL OF BAPTISM ) prescribe just how meticulously these records are supposed to be kept vatican.va/archive/ENG1104/__P2Z.HTM
Most parish sacramental records are kept in a vault or fire-proof filing cabinet at least.
Some potential problems when sacramental records are not available:
Funerals, marriages, etc.
Consider someone who is following the call to become a priest. He must produce his Baptismal and Confirmational records before proceeding. Imagine that the records were not available; then they would need to proceed with a conditional Baptism of that candidate , so as to avoid anabaptism…complications arise.
A lot of good reasons why our Holy Catholic Church does things a certain way …
I know a priest who is a White Father (Missionaire d’Afrique). He told me that rare cases do exist where individuals have been baptized because they were in danger of death, but have recovered later. They (Church) consequently kept records of these baptisms and made efforts to keep track of these individuals for the rest of their lives.
( BTW @ SnakeMauler : The salt water itself, from the ocean ,is considered to be valid remote matter (natural water) for use in Baptism … can’t comment on the rest though. oce.catholic.com/index.php?title=Baptism