There are many variables to take into account such as paddle length, body size, wind strength, sea conditions, speed through the water, etc. I have undertaken the exercise with paddlers in several different countries, some very experienced and others relative novices, using differing equipment in different weather conditions, but the results are usually the same. It is useful to compare forward paddling to driving a car with a manual gear shift. Drivers use the gears to gain optimum performance from the car in terms of acceleration and cruising over a long distance. When the need arises, say to overtake another car, it is possible to drop down a gear to produce greater acceleration.
Most modern cars use fifth gear when cruising at high speed.
But many paddlers lack the equivalent of a range of gears. Most cruising takes place in the equivalent of third gear, which is generally inefficient. Essential considerations such as body and blade positions are often forgotten. Most of the time this may not matter, except for the fact that it results in a greater expenditure of energy than may actually be necessary. There are times though, when it is necessary to be able to vary the scope of forward paddling.