A deflated giant rubber duck has sprung back to life and has been reunited with its healthier friend at the Central harbourfront, two days after withering in Hong Kong's sweltering heat.

The 18-metre yellow duck was deliberately deflated on Saturday when its rubber began to stretch after only a few hours on display.

The artwork was taken to a Tsing Yi shipyard to be inspected. It was towed back into Victoria Harbour on Monday morning and workers spent two hours pumping it back up.

Organisers vowed on social media to make their utmost efforts to protect the ducks from the elements.

The pair are expected to be bobbing around by Tamar Park for about two weeks, though one will go for a jaunt around the harbour on Father's Day on June 18, swimming by Causeway Bay and Tsim Sha Tsui.