A member of the public rescued the toddler by boat.
Dalton said people should try to swim at a patrolled beach and in between the flags as much as possible, and prepare for the conditions when heading to the beach.
There has been a dramatic surge in the number of drownings in the past two months, he said.
Water Safety NZ statistics to December 23 show there have been 66 preventable fatal drownings so far, including 26 since the start of October.
Dalton thinks people, particularly in Auckland, have been desperate to get out on the water after being in lockdown so close to summer.
He said it was great to get outdoors and go to the beach, but it was a reminder the virus is not the only safety threat this summer.
"Don't take risks, big waves are a safety threat and they might be fun for surfing, but if they hit you in the head or knock you off your board or slam you into rocks there's a huge amount of power in them.
"It's very much a case of watch for the conditions, and if in doubt, stay out."
- RNZ