Hi Genghis
That was some very good reading I thought and immediately tried the formula myself and this is what I came up with:
V = 75kn = 12.75Km/h = 38.5842m/s
g = 9.82
40° ba
9.82tan(40)/38.5842 = .4324
2pi / .4324 = 14.5309???
which is about half of what you got, I guess some difference in rounding, but where does the factor 2 come in? Did I miss something?
Cheers.