Surf industry confusion: Rocker measurement

Still after many years no one has taken the very simple and often published point of ours that rocker is never defined in the surf industry ( except in our camp it seems ) by actual rates of curvature. Rates of curvature are the only way to compare rocker on boards of different length. Failure to do this has kept longboard design in the dark ages in my opinion, and has led to much misinformation being spread about on the subject of longboard rocker.In particular it has led to dysfunctionally low rates of bottom curve being used on long boards, a problem which is particularly evident in boards of 12 feet and over in length.The point can be illustrated by examples where a very long board with what appears to be a large rocker measurement can actually have a much lower rate of rocker curve than a shortboard with smaller overall rocker measurement. Low rates of rocker lead to large overall rocker measurements when extrapolated over longer lengths, but they remain lower rates of curvature ! It's really a fundamentally important concept to grasp, and it is a necessary tool for clear discussion and comparison of rocker curves.'Flatter than your fish'This board has a lower rate of curvature than the vast majority of 'flat rockered' fish boards: