[quote=Screaming_Dude_In_Vegas][quote=9of9]Oh, it doesn't have to displace - I mean the interior only needs to be an interior cell

so the only thing you need is a working door on the boat

A 'real' interior... yes, that
would be hard![/quote]
Well the problem with that is getting the thing to move and sway. I mean I supose you could, but it would feal detached from the outside of the boat.[/quote]
True... I suppose if the entire interior is one object (like in Morrowind) it would alright - you could make it sway a bit and then the clutter would follow (which was the main reason against it, in Morrowind) although you'd still have problems with making all the larger, non-clutter, objects follow the swaying - like doors, hammocks etc.
Its usually best done by simply making the player's view sway instead (a camera trick, basically), but chances are the scripting system won't let us go quite that far.
jonajosa: Could well be! Although I did take him to mean boarding much in the same way as you could in Morrowind, I suppose they might well the boats actually float properly in the water (and perhaps even be steerable) in Oblivion just as they are
In which case it would be just the airship that would pose the problem (unless they have one of those too...

)