RULE OF TWELFTHS
3.55 m
height of tide, 2.5 h after HW
HW
LW
HW height
−
5.2 m
+
LW height
−
0.8 m
+
After HW
−
2.5 h
+
Range 4.40 m · 1·2·3·3·2·1 twelfths per hour of the fall.