The formula for theoretical hull speed (in knots) is 1.34 times the square root of the waterline length.


The distance to the horizon (in nautical miles) is 1.17 times the square root of the height of eye (in feet above sea level).


The tide rises or fall these fractions of its range during these successive hours:

1/12 during the 1st hour

2/12 during the 2nd hour

3/12 during the 3rd hour

3/12 during the 4th hour

2/12 during the 5th hour

1/12 during the 6th hour


When heeled, the draft of a vessel = (draft) x (cosine of heel angle)


Speed in knots of wind-driven current = 0.03 x (wind speed in knots)


Maximum wavelength = 1.5 times the square root of the fetch in nautical miles


Wave height = 0.026 (wind speed in knots)2