At first glance the most obvious difference from the European curves is the absence of the Spring and the Neap curves. In European tides the concern was the difference in tidal range between High and Low Water but in Pacific tides, this is no longer of any significance as it is the time difference between High and Low Water, the duration of the tide, which is key to using the curves. The Duration of Tide for ports may or may not be in areas of the oceans where there is a Semi-Diurnal Cycle of tides i.e. two High and Low Waters in a 24 hour period. In Pacific tide calculations, the Zone Time and the local time will not be UT (GMT) and it is important to get into the habit of automatically checking the Zone Time and appending it to the answer.