Three luxury yachts have gone up in flames at a Gold Coast marina, leaving a damage bill in the millions.

The three 40-foot vessels caught fire at the Marine Mirage complex at Main Beach about 2.30am (AEST).

Two of the yachts have since sunk, and the third is also likely to go down, the Department of Community Safety told AAP.

Firefighters say the blaze was extremely difficult to fight, with limited access to the scene and a limited water supply.

Crews say they were fortunate to have been able to contain the fire to just a handful of boats.

Six crews took more than three hours to put out the fire.

A floating barrier has been put into the water to contain a small amount of fuel that has spilled.

It’s believed a north-easterly breeze prevented the fire from blowing back onto other boats moored at the marina.

Police and the fire service are still investigating the cause of the blaze.

Gold Coast Area Commander Todd Murray, of the Queensland Fire and Emergency Service, said conditions proved challenging, but favourable wind conditions meant crews were able to save about 30 other boats moored in the marina.

“We had good wind conditions that helped us out there,” he said.

Mr Murray said a fourth boat had superficial fire damage, but was otherwise undamaged.