i mean sand based river waves like waimea river, there is not much water on the sand but they can get pretty fast
at 4:50, looks like waist high
i think pumping up a long street that goes upwards on a surf-skateboard, where you make that same pumping movement again and again will make one faster in that specific movement, you train cardio and at the same time that specific movement = more speed with less movement
when surfing, one is not pumping that intense and long period of a time, maybe when at very long waves, but still much less
i assume that pumping against a river wave has similar effect like surfskating upwards and also river waves are not sucking one into the wave
but if one needs to make place for the next guy of course its less time of action
paddling is complete different movement, i train it on shortboard with 27 liter volume
