Place the water, corn syrup, and 3/4 cup sugar in a saucepan and cook to 246 degrees F.
Meanwhile, whip the whites with the salt and cream of tartar in a clean dry bowl until stiff then add the 1 tablespoon sugar and continue whipping on medium speed until the syrup is ready. Drizzle in the hot syrup and then continue to mix on high for 5 minutes to cool it. Add the vanilla and water gradually to thin it out to make a sauce. Keep chilled until ready to use.
In each of 4 wide dessert bowls, place 4 slices of banana. Top them each with a small scoop of ice cream alternating flavors. Drizzle them with chocolate sauce, then alternate spoonfuls of marshmallow sauce and pineapple sauce, then sprinkle with chopped nuts.