Members of the Coast Guard are reviewing efforts to lift the wreckage of Rescue 116 today.

A specialist salvage tug has arrived in the waters off Co Mayo with the intention of partially lifting the helicopter.

Sea conditions have hampered the retrieval effort over the past week.

Coast Guard spokesperson Gerard O'Flynn says that may be the case again. 

"It's all subject to weather," he explained. "The plan today is to affect a movement of the wreck initially to facilitate an underwater inspection using a remote operated vehicle.

"It is all very subject to weather conditions, [which] are quite marginal."

The wreckage is located in waters off Blackrock Island, around 12 km from Blacksod.

Searches for the two crew members of Rescue 116 still missing - winch operator Paul Ormsby and winchman Ciaran Smith - have been ongoing since mid-March.

Crews recovered the body of pilot Captain Mark Duffy from the wreckage last weekend.