The story and dialogue were fine and the island sets were outstanding (in the elaborate style of The Land Unknown) but the terrible amateur acting and poor line delivery by a large majority of the cast left Port Sinister dead in the water.
As for the famed Giant Crab, please be advised that the stilted puppetry mentioned above only occurs for only a brief instance(they must not have been too proud of their puppet creation) with the remainder of the crab scenes being filled by closeups of a real live crab. Although I am a big fan of cheese, this two minute scene was not worth seeking out this ‘lost classic’.
For 50’s sci-fi enthusiasts, there are many other lesser known sci-fi efforts that are more deserving of your time and money than Port Sinister. Try out The Night the World Exploded, Mutiny in Outer Space, Caltiki – the Immortal Monster, War of the Satellites, Magnetic Monster, Unknown World or The Earth Dies Screaming first.
Worth a watch for fans if you happen across it on TV but Port Sinister is strictly bottom of the barrel for repeat viewings.