And another word about children:

HARKEN!
I, Snorkel Bob, inform you for the future of humanity in its subaqueous quest that:
A.) A child's mask is not like a child's shoes or shirts or trousers that the child will outgrow in six months so you might as well buy junk.
B.) A human head changes size less than 4% from birth to age 12, meaning:
C.) The mask you buy in late infancy will fit right up to drugs, grand theft auto and teen pregnancy and
D.) Those problems associated with the troubling years of sexual identity, zits, dates, grades and self-esteem can be PREVENTED by a mask with no leaks, snuks, dry rot, face squeeze and the rest.

(Size chart and how to measure for fit.)

A child who knows carefree snorkeling is among the wealthiest children in the world! Not to mention the stability factor. And I, Snorkel Bob, have the unit for you.
Come on. You want the world stuck in post-Freudian trauma from cheapo junk mask syndrome and the womb implosion nightmare? I, Snorkel Bob, think NOT! The Li'l Mo™ will avoid the bleak future.
SILICONE OF THE SURGICAL GRADE, THIS ONE (GRADE 1 out of 18). THIS MASK FITS FROM AGE 0.1 TO EARLY PUBERTY. $35

And don't forget!
I, Snorkel Bob, also offer Kid's Fins, Snorkels & Snorkel Vests