Dubai Ports Police rescued an inspector after he fell into a tank by the dock near Dubai Marina, police said on Thursday.
The man fell into an 11-metre storage tank containing 4-metres of foam used in firefighting, according to Lt Col Ali Al Naqbi, head of the Marine Rescue Division.
He said rescue and special tasks teams rushed to the scene but struggled to extract the man due to the tank's narrow opening.
The teams had to work quickly as air within the tank was limited, he said.
Similarly, the upper and lower access points to the tank were unsafe, Lt Col Al Naqbi said. Police lowered the man an oxygen bottle to help him to breathe clean air.
The rescuers entered the tank carrying more oxygen canisters and used a large crane to extract the inspector. He was immediately transferred to an ambulance to receive first aid.
Lt Col Al Naqbi said the man has since has recovered from his ordeal but did not disclose what the inspector was examining.