Let's imagine that every wave is a small, one-off event that just happens to take place around millions of similar one-off events. All of these waves are capable of interacting with each other, although normally that doesn't mean much. If, however, two of these random interactions are going in the same direction at the same time, they come together to form a bigger wave. Given how many of these waves are milling around, it makes sense that several could merge into one massive ship-threatening rogue wave.

The traditional way to predict rogue waves like this is to build a system that's similar to a weather-modeling setup. That's what takes all the power, but the Sapsis/Cousins method just needs LIDAR, RADAR and, presumably, a laptop to do the actual number crunching. The new algorithm just looks at the length and height of all the waves in the vicinity around the ship. If a wave is high and wide enough, then there's a far greater likelihood that it'll become problematic in the very near future. Once these rare waves are spotted, it's just a case of sounding a horn and getting everyone off the deck before trouble strikes.