Unfortunately yes, and I think that for an in game item that players can purchase with real money, this is not a good thing for the game.
Personally, I'd much prefer that upon decaying the Britannian ship, rather than simply vanishing althougether, would transform back into "deed form" and be placed into the Bank Box of the Character that owns it.
The hold's content would be lost (would get deleted during the process of changing the Ship into "deed form") but at least the player who bought it with real money would not loose it because it vanished totally....
Also, this would still ensure that the Sea Lanes would not be annoyed by a number of non decaying large ships.