The sound of laughing children filled the air as hundreds of people packed the new $4.75m Port Douglas Splash Park for the launch on Saturday.

Mermaids were perched on rocks surrounded by curious kids and the Sea Circus crew roamed around on stilts and with fairy wings on.

The DJ was pumping out the tunes, free ice creams were popular, and a host of politicians were busy making their own social media reels - including a rare appearance in Douglas Shire by new Federal MP Matt Smith.

The park had already proved popular since it opened the previous Thursday with a soft launch for school children - several visits by Newsport leading up to the official launch revealed the word was already out in the local community that the water was pumping.

The new tourist attraction officially opened on Saturday, September 20, with a full day of festivities put on by Douglas Shire Council.

After Mayor Lisa Scomazzon counted down from 10 to one, the children rushed in to enjoy the fun.

And, from 5-8pm, a Splash Park After Dark event included choreographed water fountains and coloured lights.

The reef-themed splash equipment includes reproductions of manta rays, crabs and jellyfish.

Douglas Shire Council has received State Government grants of more than $2.5m for the park, and has paid about $2.2m itself, with Townsville-based JMac Constructions building the centre.

The Port Douglas Splash Park is located at Jalunbu Park, Garrick Street, Port Douglas, behind the Surfy, and is open across the school holidays.

Pictures: Santiago Gonzalez, Shaun Hollis