There has always been ocean lore that proclaims rogue, monster waves rising 80, 90, or 100 feet high or more. Of course, these are not eye-witness accounts. Men in wooden ships don’t survive such an encounter. There was the story of the Alaskan Tlingit Indian woman who returned from berry picking to find her entire village disappeared. The debris field evidence on the shoreline indicated that the ocean had risen up and fell upon the village. The wave would have been more than 100 feet high to cause the damage. Experts of the day dismissed stories about such waves because they seemingly violated basic principles of ocean physics.
What explains this phenomena? If you would like to read about a theory to explain rogue waves that use LDT (large deviation theory), a bit of nonlinear Schrödinger equation application then click here.While the article does get a bit wonky from time-to-time, it is an easy read. One of the example they use in developing prediction models is a comparison to casino gambling. “A casino would be wise to carry enough cash to cover a situation where one player won three straight roulette bets using a lucky number, since a three-spin hot streak is likely to happen every 50,000 visits. But it can safely ignore the possibility of 10 straight wins, which would require, on average, 100 trillion spins.” When it comes to uncommon events, you can estimate odds quite accurately by focusing on the least rare event, rather than exhaustively tallying up every possible outcome – and so three spins will suffice. LDT operates between on the even more rare events and allows calculations of likelihood. By analogy, algebra can only do so much and then one needs to move onto calculus. LDT is the hinterlands of probability science.
Not your thing? Here’s a good read: The Wave: In Pursuit of the Rogues, Freaks, and Giants of the Ocean available on Amazon. The author interviews mariners, wave scientists, insurance companies and extreme surfers! It is a fascinating book.