This has already been answered. Baptism by desire suffices for salvation, especially if it is explicit.
Again, infallibly dogmatic: Baptism is necessary for salvation. You cannot disprove the norm by the exception. Baptism of desire is necessary for salvation. Read St. Matthew's Gospel, the last few sentences of the last chapter.
Matthew 281. After the Sabbath, at dawn on the first day of the week, Mary Magdalene and the other Mary went to look at the tomb.
2. There was a violent earthquake, for an angel of the Lord came down from heaven and, going to the tomb, rolled back the stone and sat on it.
3. His appearance was like lightning, and his clothes were white as snow.
4. The guards were so afraid of him that they shook and became like dead men.
5. The angel said to the women, "Do not be afraid, for I know that you are looking for Jesus, who was crucified.
6. He is not here; he has risen, just as he said. Come and see the place where he lay.
7. Then go quickly and tell his disciples: `He has risen from the dead and is going ahead of you into Galilee. There you will see him.' Now I have told you."
8. So the women hurried away from the tomb, afraid yet filled with joy, and ran to tell his disciples.
9. Suddenly Jesus met them. "Greetings," he said. They came to him, clasped his feet and worshiped him.
10. Then Jesus said to them, "Do not be afraid. Go and tell my brothers to go to Galilee; there they will see me."
11. While the women were on their way, some of the guards went into the city and reported to the chief priests everything that had happened.
12. When the chief priests had met with the elders and devised a plan, they gave the soldiers a large sum of money,
13. telling them, "You are to say, `His disciples came during the night and stole him away while we were asleep.'
14. If this report gets to the governor, we will satisfy him and keep you out of trouble."
15. So the soldiers took the money and did as they were instructed. And this story has been widely circulated among the Jews to this very day.
16. Then the eleven disciples went to Galilee, to the mountain where Jesus had told them to go.
17. When they saw him, they worshiped him; but some doubted.
18. Then Jesus came to them and said, "All authority in heaven and on earth has been given to me.
19. Therefore go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit,
20. and teaching them to obey everything I have commanded you. And surely I am with you always, to the very end of the age."