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The limit for no decompression amatuer sport diving with either SSA or PADI certification is 42m. Professional divers can and do go much, much deeper using Heliox mixtures. 48m is a walk in the park for a professional in the good visibility apparent from the photos I've seen of the wreck.
My wife and I used to dive inside ship-wrecks on air at those depths pre-kids. It was not a problem back then.