If my google-fu and living alone skills have taught me anything, the density of seawater is just making sure you boil the water with salt.
You are suppose to salt the water before boiling most ingredients, as the salt gives it more flavor and because salted water has a higher boiling point, the water will be hotter, which in turn cooks the pasta better.
My wife is a chef, and you got gold star mate.
Though "as dense as sea water" is a little overboard. I put maybe half a teaspoon for twice what it looks like Reimu's got.
