Have the boat out of the water when you change the name so the sea gods don't know. The worst that will happen is that you will not win the lottery that week. This is a fact, I know because thats what happened to me.
The old wives tale stems back to when we had a merchant navy. Ships were owned by the companies that imported goods from all over the world and were therefore recognised in all the worlds ports and associated with the companies that owned them. When the companies hit hard times the ships were sold off and the new owners changed the name so as not to be associated with the failing company. As the smaller companies failed the ships names kept changing whereas the ships ownerd by the sucessful companies stayed the same. In time the folk law evolved that bad luck was associated with changing ships names.
I've changed the names of my last 3 boats and the only bad luck we've had is running out of beer on a couple of occasions. The boats themselves have always met our fullest expectations and brought us home safely.
Once bought a boat called "Sea Reason",wasn't mad on the name so spent a couple of hours with a hot air gun peeling off the vinyl stickers only to find the name "Jolly Charlie" painted on underneath.Anyone know how to re apply sundry bits of vinyl sticker??