Worthless (with one exception)
And that is the beautiful New Zealand scenery. Everything else in this waste-of-time is a .....well, waste of time. The acting of Warren and Peppard is atrocious. And if Donald Plesance was one of your favorites before it won't be after you view this. He is the central figure in this movie and his drunken sot character (kind of like Walter Brennan on a binge) will definitely get on your nerves. The only redeeming feature is the jet boat chase and even that managed to kill two stunt men during filming.
Suffice to say it would be possible to pick this movie apart piece by piece and it could easily become an example of how not to do a movie but it simply isn't worth the effort.
If you want to watch the scenery, which is generally outstanding, turn off the sound and enjoy. Otherwise, skip it. You haven't missed a thing.