One can easily see that Roman Polanski was trying to ride on the success of his early comedy 'The Fearless Vampire Killers!' when making this film. The protagonists and love interests in both films are nearly identical, however in 'Pirates', the cast and crew do not manage to do nearly as good as a job. To be fair, some of the crew give good contributions, such as the costumes by Anthony Powell, and Philippe Sarde's great music score, however these points barely atone at all for the overall picture. It is more often stupid than it is funny, with the same old jokes recycled during the film - the shark pun fails particularly poorly. It is mostly just a mixture of being absurd and revolting, with little in the way of a story, and towards the end it is just messy. It could be argued that Matthau gives it his all - perhaps he does - but the results are not too great. There is enough in this film to save it from being an utter disaster, but still, it is not a very good film.
