Lunar Semidiurnal Tide (M2)
The chart shows the lunar semi-diurnal or M2 tide. The colours represent the amplitude of the tide and the lines represent the phase. The phase lines go from 0 to 360 degrees indicating that, at any time, there is a high tide somewhere on the NZ coast (see the animation - 135KB). The amplitudes vary from 0.3 m around Kapiti Island to 1.4 m in the Firth of Thames and in Tasman Bay.