It’s easy to forget the enormous size and power associated with waves in the ocean. Yes, we see pictures of surfers on Hawaii or of ships in waves occasionally, but usually we don’t really think about how large waves out in the ocean actually are. Which makes it easy to underestimate the force that the ocean holds within, not only on days when natural disasters like storm surges or tsunamis occur, but on a daily basis, just in the swell of distant storms. So sometimes it is quite healthy to look at waves on the beach and compare them to other buildings.
For example here, waves and Hastings Pier:
Those aren’t even particularly large waves, yet we see that their wavelength, peak to peak, is easily a lot more than 20m. This is what coastal structures deal with on a daily basis!