Richard - I was very interested in your post for two reasons:
1) I have just started hunting San Francisco Bay from a kayak and would love to be in touch with others using this method - I have a lot to learn. 2) My first and best beloved shotgun is a Brno ZP49, but it is in Africa, and the only gun I have here that can handle steel is a peculiar contraption with only one barrel, one trigger, and all sorts of clickety-clack innards. So learning that CZ makes a duck worthy hammergun with a respectable number of barrels is wonderful news.