Preheat oven to 350°.
In heavy skillet, over medium heat, cook sugar, stirring constantly until melted and caramel-colored.
Pour into ungreased 9-inch round layer cake pan, tilting to coat bottom completely.
In medium bowl, beat eggs; stir in water, sweetened condensed milk, vanilla and salt.
Pour over caramelized sugar; set pan in larger pan (a broiler pan).
Fill larger pan with 1 inch hot water.
Bake 55 to 60 minutes or until knife inserted near center comes out clean.
Loosen side of flan with knife; invert onto serving plate with rim.