John Treacy is heading up the San Marcos project, the search for another Spanish Armada vessel off Clare.
He visited Streedagh following the discovery of timbers which he believes are from a rudder post on one of the 16th century ships. Mr Treacy echoed calls from the local Grange and Armada Development Association (GADA) for an urgent survey to assess whether the Spanish Armada vessels have become unstable.
The Department of Heritage confirmed a dive inspection of the site would take place in the coming weeks, when weather conditions improve, to assess the condition of the three wrecks.
Donal Gilroy, a member of GADA, which helped retrieve the two pieces of wood washed ashore at Streedagh last week, has formally handed them over to the receiver of wrecks, which means they are now in the care of the State.
They remain submerged in salt water close to Streedagh, pending transfer to the National Museum.
“My worry is that only 10% of what is being lost from the wrecks is being washed ashore and 90% could be swept out to sea,” Mr Gilroy said.
“That’s why we need an underwater survey to see how much movement there has been and to assess the damage that has been done.”
The National Monuments Service will next week inspect the timbers found “to try and ascertain what part of the wreck they originally came from”, said a spokeswoman for the department.