Unfortunately, we can't cut open every board and analyse it in the lab. But we can paddle it, tow it, roll it in - exactly what every paddler does. Over the course of months, we have determined a mountain of performance data, which in the end are soberingly close to each other. For example, a particularly fast inflatable, such as the Starboard 11'6", is perhaps five per cent ahead of the slower boards in the group over long distances. The differences can hardly be determined more precisely, as factors such as wind or current fitness are too varied. After many kilometres with the boards, the basic characteristics of all the candidates were very clear in the end - and very different.
Five per cent, which does not translate into a big time advantage even on long journeys. However, the advantage of the narrower, sleeker shapes is that less power is required for the same travelling speed. The same applies to hardboards in particular. Narrow boards run more easily after each paddle stroke and hardboards "glide" a little better. In an internal comparison of two sporty, fast shapes, 7.2 km/h on the fast inflatable requires consistent paddle pressure and allows a moderately fast stroke rate. The hardboard paddles more easily at the same speed, you can increase the stroke rate and perhaps maintain three to five per cent more speed.
You can find the complete fact check comparing all 17 boards in the "hard or soft" category in SUP Magazine 2018, which you can still order below: