That's incredible. I was just speaking with colleagues about the best conditions for surfing waves. The best waves here in California originate in storms on the opposite side of the Pacific. The waves travel thousands of miles over the course of days without appreciably dissipating.
The waves do dissipate, but the dissipation and attenuation is what makes the best waves. In the storm the waves are huge and messy with all kinds of frequencies interfering with each other. Attenuation means the high frequency / small amplitude waves dissipate the quickest and the lowest frequency / high amplitude waves dissipate the slowest.
By the time they've moved a long way, all that's left are the lowest frequencies which makes for a clean smooth wave. The amplitude will have reduced compared to the original storm, but that original long period is still there creating nice long gaps between the waves. This is why surfers care about the period of an incoming swell - it's a proxy for how the swell has cleaned up on it's travels.
The best waves come from the biggest storms the furthest away.
