I'm sixty years of age, a die hard movie fan, and a lifelong Duke fan. I saw this for the first time today. I was drawn into the story despite the real war footage which didn't match the live footage, the fact that the ocean floor looked exactly like the bottom of a fish tank (I kept looking for the diver and treasure chest) and parts of the cliched script.
Despite those handicaps, it's not a bad movie. You have to enjoy the relaxed relationship between Duke and Bond, some of the young actors (Bill Campbell, Paul Picerni) and that Jack Pennick fixed the torpedo problem.
I found I could suspend modern film effects and just role with the plot.
Average Duke is better than most any other highly touted actor at his best.
We deal in lead, friend.