That's great paddling advice. With how hard we got to battle to chase shifty peaks on east coast beach breaks, paddle efficiency has been a big focus of mine. The path described here is very good advice. I focus on digging deep and burying my elbow then pulling down and towards the center of body at a 45 then rotating palm outwards to the other 45 and kicking back and out on the follow through. I get the most out of each paddle making it a compound movement rather than quantity of strokes where some dudes just slap at the water like they were doing a broked doggie paddle. Not sexy.
Is that a 45 degree angle, and not a 47 1/2 degree angle?