It should be viewed for what it is
I just saw this movie on DVD last night. I added it to my Netflix queue figuring it would be a good laugh, which in parts it was. I see that the movie was made in 1980, 5 years before Bob Ballard and his team even discovered the wreck. I presume that no one had actually viewed the wreck of the Titanic prior to that?
The movie (and book, I presume) make A LOT of assumptions. The largest one being that the ship, after some 70 years on the floor of the Atlantic, is in perfect condition. Even if the ship had sunk in one piece (which we now know it did not), just the shock of the ship hitting the ocean floor would have surely caused more damage to it.
Even more preposterous than the idea of raising the wreckage of a ship that sunk decades before was the idea that the mineral would still be aboard - and, in the end, it wasn't.
I'm definitely no expert on the wreckage of the Titanic (go to Bob Ballard for that). But I believe that the actual wreckage is now so totally weak from being eaten by microbes at the bottom of the Atlantic, it could never be raised. In the movie, it looks as if the wreck is left at dry dock in NYC, where it was scheduled to dock back in April 1912.
I also wonder what any of the survivors of the sinking (all are now deceased, I think) thought of this movie.