I don't know if I can offer any clarity in the S.A. liveaboard issue but I may be able to add to the confusion [}: )]
Hout Bay harbour is administered by Marine and Coastal Management. Quite simply, I think therefore that MCM make the rules in this case.
As far as living on board is concerned in a more international perspective, most countries seem to discourage it. Why, I don't know but I suppose it goes against the grain. Politicians don't like people who are difficult to control and, by definition, anyone who lives on a boat and can at any time sail over the horizon becomes difficult to control.
In Sweden (my home country) it is not allowed. One must have a permanent address ashore. Having said that, some do have an address ashore (sister, mother, friend etc.) and then live aboard anyway. The bizarre thing though is that whilst one is not allowed to permanently reside on a boat, for the puroses of searching a boat the cops need to get a search order from the magistrate in exactly the same was as they would for a house. Mixed messages!
I would welcome a lawyer's view on this subject, especially regarding the possibility of taking any decission by local or national authorities banning liveaboards to some higher instance, such as the European Court of Justice.
Good luck - and maybe we'll meet in Hout Bay. I'm in Cape Town at the moment.
......wannabe liveaboard (only my boat is in Europe)