From a first swim class to a splash in the backyard pool, baby boys can wear one-piece swim rompers, rashguard swimsuits, swim trunks or rashguard-and-shorts sets. Most run 0-3 or 3-6 months to 18-24 months, and a few Deux par Deux pieces go on into kids sizes.

Petit Lem has printed swim rompers, including long-sleeve styles, and two rashguard and swim shorts sets. Hatley offers one-piece rashguard swimsuits in shark, dinosaur, tropical ocean and whale prints. Miles The Label adds printed and color-block swim rompers, and Deux par Deux has dinosaur-print swim trunks, a short-sleeve rashguard and a long-sleeve one-piece rashguard.

Between dips, a hooded towel from our kids beach towel collection keeps him wrapped up, and hats and caps for kids help shade his head outdoors. If an older brother swims too, boys swimwear continues up to youth XL, while a baby sister will find swimsuits and rashguard sets in baby girls swimwear.