Queensland Rail's fleet of old electric multiple units (EMU) are being progressively replaced with the New Generation Rollingstock, which are being fixed to comply with disablity laws after being described as flawed "from day one".

However, rather than end up on the scrap heap, a proposal is being considered by the government to turn a few of the old trains into an underwater tourist attraction in south-east Queensland.

A petition, lodged in the Queensland Parliament, is calling for a small number of the fleet of 87 EMUs to be reused as an artificial reef in Moreton Bay when they are retired.

Transport Minister Mark Bailey said he was happy to look at the idea.

"I like the idea of seeing these old trains support new life as artificial reefs in Moreton Bay or somewhere else appropriate along our coast and have previously requested Queensland Rail to examine it further," he said.

"That said, any plan to sink trains to the sea floor would need to be carefully considered from an environmental, maritime, tourism and cost perspective."

Queensland's Department of Environment and Science has advised Queensland Rail it would consider a proposal to use two or four retired EMU or inner-city express [ICE] train units for an artificial reef.

Decisions would have to be made on whether the site would be used for marine life or also as a dive site.

Depth, access, stability in storms and maintenance would also need to be considered.

It is understood the department preferred to use artificial reefs constructed from highly productive, stable, purpose-built reefs with expected life spans of more than 30 years over scrap metal.

No firm proposals have been received and no funding has been committed to the project or a feasibility study.

Greens MP Michael Berkman, who sponsored the petition, said supporting the voices of constituents was a great part of his job.

"The wrecks at Moreton Island are an amazing tourist attraction, and another artificial reef that commemorates Brisbane's well-loved trains is definitely worth considering," he said.

"The state and federal government would need to conduct a rigorous environment impact assessment, and traditional owners should get final say, but a "rollingstock reef" could be a beautiful addition to Moreton Bay."

Rail lobbyist Robert Dow said the retired EMU trains were currently being stored in stabling yards.

"As to suitability for a reef, I'm not in a position to say either way, but my gut feeling is they're too fragile and I don't think they'd last too long in the ocean," he said.

"They're not like a ship, a ship is designed to be in the sea to a certain degree."

There are several artificial reefs in Queensland, including at Moreton Bay, the Great Sandy Marine Park, ex-HMAS Brisbane, and ex-HMAS Tobruk.

Dive operators declared the sinking of the ex-HMAS Tobruk a "stuff-up" after it landed on its side, although the Queensland government said a report showed it could still be accessed by beginner divers.