Melt chocolate with water over low heat, stir until smooth. Stir in first amount of sugar and the salt. Bring to a boil over medium heat, stirring constantly. Reduce heat and simmer 5 minutes, stirring constantly.
Blend a small amount of the hot mixture into egg yolks. Stir into remaining hot mixture. Cook and stir one minute longer. Cool to room temperature and add first amount of vanilla.
Whip cream with sugar and vanilla until soft peaks form. Fold into chocolate mixture. Pour into a container and freeze until firm.