Peel the peaches by blanching them in boiling water for about 30 seconds, then transfer them to an ice bath. Once cool, the skin should come off easily with a paring knife. Cut the peaches in half and remove the pit.
In a medium saucepan, combine water, sugar, and vanilla bean. Bring the mixture to a simmer and stir until the sugar has dissolved. Add the peaches to the pan and poach them for about 5 minutes or until they are just tender. Remove the peaches from the syrup and let them cool. Reserve the syrup.
In a separate saucepan, combine the raspberries and sugar. Cook over medium heat until the raspberries have released their juice and the mixture thickens, about 10 minutes. Remove from heat and strain through a fine-mesh sieve to remove the seeds.
Whip the cream until stiff peaks form.
To assemble the Peach Melba, place a scoop of vanilla ice cream in the center of a plate or bowl. Place a poached peach half on top of the ice cream and spoon some of the raspberry sauce over the peach. Repeat with the remaining peaches, ice cream, and raspberry sauce.
Place a dollop of whipped cream on top.