Place egg whites in the clean, grease-free bowl of stand mixer (you may use a large bowl and an electric mixer instead, but there is a lot of mixing required and even using a hand mixer will be an arm workout). Set aside.
In a medium-sized, heavy bottomed saucepan, combine sugars, corn syrup, and water.
Cook mixture over medium-low heat, stirring frequently, until sugar dissolves. Use a damp pastry brush to wipe down sides to keep sugar crystals from forming.
Once your sugar dissolves and the mixture begins to come to a boil, stop stirring and attach your candy thermometer.
Continue to cook to 255F (124C) but once your mixture reaches about 240F (115C), keep an eye on your temperature but return to your egg whites in your stand mixer. Add the salt and use a whisk attachment to beat your egg whites and stiff peaks form** -- this can take several minutes even on the highest speed. Be sure to pay attention to your syrup on the stovetop, and let your stiff peak mixture sit while you wait for that to reach 255F.
Once syrup reaches temperature, remove from heat and drizzle in a slow, thin stream into the bowl with your stiff peaks while beating on high speed Be careful, go slowly or there will be some splatter! You can start on low speed and gradually increase the speed to high as you are adding the syrup.
Continue beating the mixture until it holds its shape. the mixture will become glossy and very thick, and this will take several minutes. Beat until it is stiff enough to hold is shape when the whisk is raised from the mixture.
Use a spatula or a wooden spoon to stir in your vanilla and chopped nuts.
Use a pair of lightly buttered spoons to drop the mixture by 1 1/2 Tablespoon-sized portions onto a wax or parchment paper lined tray, swirling each drop into a peak.
Let the tray of Sea Foam stand until it is completely dry, this could take several hours or it may even need to sit overnight.