Water Safety Ireland and the Coastguard are warning the public against using inflatable toys in open water.
It says they pose a drowning risk and parents should never allow them to be used at rivers, lakes or beaches.
Water Safety Ireland Deputy CEO, Roger Sweeney says inflatable toys can sweep a child away.
"These toys are vulnerable to the slightest breeze or current and they can easily take a child away from shore," said Mr Sweeney.
"Drownings typically occur when people overestimate their ability and underestimate the risk.
"The risk is a toy could take a person out of their depth and out of their comfort zone.
"This is further compounded if the toy deflates and the person tries to swim or paddle a partly deflated toy to safety.
"Cooler water can quickly cool the muscles needed for swimming and hidden currents can make this swim very difficult and sometimes impossible.
"These toys provide a false sense of security and should be avoided."
Lifeguards trained by Water Safety Ireland have also seen an increase in the use of inflatable toys such as air mattresses, boats and inflatable rings.
Both organisations have called on everybody to redouble their efforts to ensure that basic safety precautions are observed when recreating on or near the water.