The big waves like Jaws, Nazare' and other places hitting 60 to 80 foot plus waves the surfers are hitting over 40 to 50 mph. The big waves are moving over 20 mph and the speed going down the wave is probably around 25 plus. We used to surf behind water ski boats all the time way back in the day and would hit over 50 mph. Used to be able to make it though a slalom course on a Sunset single fin 6'2" Shaun Tomson board. This was at Cypress Gardens Florida back when it was the water ski capital of the world.
Was down in the DR decades ago on the north shore during a record winter north swell. We were shooting a tourism film of the whole country for over a month. Beautiful country with over 10,000 foot mountains. What a coast line. For a couple of weeks we were flying around helicopters shooting the beaches and to land in certain places. The waves were over 15 feet up and down the coast and we were flying right over the top of these waves. This was for days from Puerta Plata to Samana Bay.
We were staying at Sosua bay for a couple of days and ended up hitting a couple of those waves at probably over 12 feet.