I'm baptizing my twins next month and while I have god parents for the church, I was thinking about having water god parents as well. I know its a blessing that typically takes place before the christening as a way of protecting them before they are brought before God in the church (at least that is the way it was explained to me).
Who can perform such a blessing? Does it have to be a priest? Are there specific readings or blessing done? Any other info would be helpful.

TIA