There are definitely prescribed rituals for renaming vessels, and those that ignore them do so at their own peril.
However, I am one of those. We have renamed a number of boats over the years without bowing to the superstitious warnings of those that believe. We have not had any problems (he says as he raps his knuckles on the nearest piece of wood)
So is there anything to all this renaming nonsense? To my mind probably not - but its fun to read about the best ways to do so. Try this: http://www.namethatboat.com/boat-renaming.htm
And make your own call.....