St. Paul writes:
1 Cointhians 10:1-2
(1) Moreover, brethren, I would not that ye should be ignorant, how that all our fathers were under the cloud, and all passed through the sea;
(2) And were all baptized unto Moses in the cloud and in the sea;
When the Israelites passed through the sea, they were not immersed where they? They were sprinkled, because Paul clarifies that they were baptized by passing through there, yet we know they were not immersed, yet baptism must in any case always have water making contact with the person. To purify people in the Older Covenant, sprinkling was done, not immersion; and we are told by Isaiah in Isaiah 52:15 that Christ would “sprinkle” many “nations” (nations include children).
And also consider what the Spirit says through St. Peter:
1 Peter 3:20-22
(20) Which sometime were disobedient, when once the longsuffering of God waited in the days of Noah, while the ark was a preparing, wherein few, that is, eight souls were saved by water.
(21) The like figure whereunto even baptism doth also now save us (not the putting away of the filth of the flesh, but the answer of a good conscience toward God,) by the resurrection of Jesus Christ:
(22) Who is gone into heaven, and is on the right hand of God; angels and authorities and powers being made subject unto him.
Peter relates “baptism” to Noah’s flood directly.
Who was fully immersed in the flood? Clearly it was the non-believers; yet Noah and his family were sprinkled by rain, a figure of which is baptism according to Peter.
The Egyptians were the ones immersed. Are you sure you want to be immersed?