"It must take quite a while to build something like that though, wouldn't it? And once you have done so, the list of those wanting to accompany you will probably be incredibly long."

Although perhaps it depends on the style of the craft. Simpler designs, like those the orcs or the island dwarves use - there might be enough resources here to make a few such boats, capable of holding ten people rather than the broad galleons of the navies. There would be less competition for their use, if they could make a few - and one could be more easily stolen and hidden away offshore somewhere.