The sea was foamy, my friends, like an old man at a deli trying to return his parfait

Here's a recipe for Seafoam [er Meringue]

Meringue Recipe - Add a Pinch
https://addapinch.com › By Course › Dessert Recipes
Mar 19, 2012 -
meringue from addapinch.com

Whip the egg whites until they are glossy and smooth, then add the cream of tartar to help the egg whites hold their form. Slowly add the sugar to the egg whites. Spread meringue on top of pre-baked or no-bake dessert, place about 4 inches under the heat and bake for about 10 minutes, until golden.

Meringue is a type of dessert or candy, often associated with Italian, Swiss, and French cuisine, traditionally made from whipped egg whites and sugar, and occasionally an acidic ingredient such as lemon, vinegar, or cream of tartar. A binding agent such as salt, corn starch, or gelatin may also be added to the eggs. Wikipedia
Place of origin: Disputed; either Italy, France, or Switzerland

[Results of increasing amounts of "wave action"]

1. https://thetoughcookie.com/wp-content/uploads/2014...
2. https://thetoughcookie.com/wp-content/uploads/2014...
3. https://thetoughcookie.com/wp-content/uploads/2014...
4. https://i.pinimg.com/originals/2e/02/b0/2e02b06a8a...

The difference is that the natural recipe [i.e. Seafoam] varies in detail [such as the list of "ingredients"] depending on the location and the time of year, etc. -- the one constant requirement is agitation and aeration provided by wave action and something to make it stick and persist such as decayed algae

Note one common thickening agent for commercial food products is Calcium or Sodium Alginate --derived from You guessed-it Algae
https://www.modernistpantry.com/sodium-alginate.html

Sodium Alginate (E401) is extracted from brown seaweed.
It is used as a stabilizer for ice cream, yogurt, cream, and cheese.
It acts as a thickener and emulsifier for salad, pudding, jam, tomato juice, and canned products.
It is a hydration agent for noodles, bread, cool and frozen products.
In the presence of calcium and acid mediums, it forms resilient gels.
It is a cold gelling agent that needs no heat to gel.