In a small saucepan, combine the cream, butter and the vanilla bean and seeds. Bring to a simmer, then remove from the heat.
In a heavy, medium saucepan, cook the corn syrup over moderate heat until bubbling. Sprinkle in 1/4 cup of the sugar and cook, stirring just until the edges begin to turn a light amber, about 2 minutes. Repeat with the remaining sugar, adding 1/4 cup at a time. Once all of the sugar has been added, cook the corn syrup mixture until a medium-amber caramel forms, stirring and swirling the pan, about 5 minutes.
Remove the caramel from the heat and carefully add the cream mixture. Cook the caramel over moderate heat, stirring frequently until any hardened sugar melts and the caramel is bubbling, 2 to 3 minutes. Let cool slightly, then whisk in the water. Remove the vanilla bean and serve warm or at room temperature.