The term "Advanced" seems to annoy some people... regardless of what you call it, the fact that one is getting additional education - hopefully with a good instructor/mentor is a good thing.
However, even if this person has an Advanced Trimix Cert. with hundreds of dives, if this diver has only been diving in one particular environment - i.e. warm clear water, then if this highly trained diver chooses to dive the cold murkier waters of the NorthEast Atlantic in the U.S. then they are effectively a beginner... or at the very least need to ease into learning to dive this environment and gain experience in these conditions before tackling the Andrea Doria.
Experience, certifications, and qualifications can be very relative.
However, even if this person has an Advanced Trimix Cert. with hundreds of dives, if this diver has only been diving in one particular environment - i.e. warm clear water, then if this highly trained diver chooses to dive the cold murkier waters of the NorthEast Atlantic in the U.S. then they are effectively a beginner... or at the very least need to ease into learning to dive this environment and gain experience in these conditions before tackling the Andrea Doria.
Experience, certifications, and qualifications can be very relative.