Drowning can happen quickly and is the leading cause of death in children between the ages of 1 and 4. The number one rule is to NEVER leave a child unattended around or in a body of water. There should always be at least one adult, who is sober, able to swim, and knows how to administer CPR, supervising children around water. Consider having a designated water watcher whose sole responsibility is monitoring the children in the water.
It is also incredibly important to get your child swimming lessons. According to the American Academy of Pediatrics (AAP), infant swim lessons do not appear to reduce drowning risk (though it can still be a fun bonding activity) and it is recommended that children start lessons as a layer of protection against drowning beginning for many children starting at age 1. Here in Southington, the Recreation Department, YMCA and Mountain Grove Swim Club (for members only) offer swim lessons.
Just like dressing your child in bright colors makes it easier to spot them in a crowd, a neon-colored swimsuit makes it easier to spot a child in the water (both at the surface and under the water). Alive Solutions did multiple tests showing the best colors to wear in various bodies of water, as well as testing the effect of patterns on visibility.
It is also important to consider the use of Personal Floatation Devices (PFDs). Standards and recommendations for PFDs are set by the US Coast Guard, which you can learn about here.
Car seats are not built with the intention of being buoyant or to be used as flotation devices. Infants and babies should be held by an adult when near the water or on a boat.
Learn more about Water Safety
https://www.redcross.org/get-help/how-to-prepare-for-emergencies/types-of-emergencies/water-safety/water-safety-for-kids.html
https://alive-solutions.com/water-safety/
https://www.safekids.org/poolsafety
https://www.watersafetyusa.org/