1. In a medium saucepan, combine the water and red rice and bring to a boil. Add a large pinch of salt, cover and cook over low heat until just tender, about 20 minutes. Uncover and simmer, stirring occasionally, over moderately low heat for 10 minutes. Add the coconut milk and simmer until the liquid becomes very thick, about 35 minutes.
2. Meanwhile, in a small saucepan, combine the heavy cream and vanilla bean and bring to a simmer. Cook for 3 minutes, them remove from the heat, cover and let steep for 20 minutes. Scrape the seeds from the vanilla bean into the cream; discard the bean.
3. Stir the sugar into the cream until dissolved. Stir the cream into the rice and let stand, covered, for 30 minutes. Serve warm.
Make Ahead: The red rice pudding can be refrigerated overnight. Reheat gently before serving.