Why Are Ships Launched with Champagne?

In ancient days, ships were christened with human blood as an offering to the sea gods, so that they would have this offering and spare the blood, actually the lives, of the men on board the ship.

As men became more civilized, the blood of animals was used, and later, red wine and champagne.

Even today, the future of the ship is in doubt if the bottle of champagne doesn't break over the bow during the launching and christening ceremonies.