I think you may be missing something:

"The following items are prohibited and their possession is not allowed on board any Company ship by passengers or crew without a valid lawful reason....and only with consent of the Ship's Master."

Emphasis on: 'without a valid lawful reason' and 'only with consent'.  Do you have a valid lawful reason for possessing a ham radio (or a laser pointer)? Then it may be okay. And that's what they are telling you in the second link that lists exemptions to those prohibitions. 'It's okay for ham radio use on board... but not for you to use to listen to the crew conduct ships business, talk to other ships in the harbor, and so on.' That way they can speak to the issue of your activities of such gear, not just the fact of possession of it.

This is legalese so that someone can't just bring anything on board they want, claim it's ham radio (or in the case of a laser pointer, claim it's for a fictitious power point presentation), and claim a right of possession. They are saying to anyone/everyone...  'We don't let you bring these things on board willy nilly without a reason and if we don't like your reason, we can boot your stuff off the boat and there's absolutely nothing you can do about it; you have no recourse.'  I believe the term 'exerting positive control' is used in other professions for such a situation...

73 and enjoy your cruise!  Kevin N4UFO