Spring and Neap Tides Formation, ATT (Admiralty Tide Table) Explained

Good evening. So, today we will learn about tides. The tides are basically caused by the sun's and moon's gravitational pull. Also, the tides are of two types mainly, the diurnal and semi-diurnal. Diurnal means there is one high tide and one low tide per day and semi-diurnal means there is two high tide and two low tides per day. Suppose, both the sun and the moon are in the same position and the earth is here, their gravitational pull is high. They are combining the pull, so this is a spring tide and this spring tide, the high water will be higher than the other spring tide. Next comes the neap tide. At neap tide, the moon is basically at 90 degrees to the earth and the sun is exactly 180 degree. So, the pull is combined. One pull will come from here, the next pull will come from here. In this position, the pull of the sun is reduced by the pull of the moon. So, this causes a neap tide. The same comes again when the sun and the moon are in opposite direction and the earth is in the middle. Same in this position also, a spring tide will be caused and again a neap tide will be caused when the sun and the moon are at 90 degrees. So, in the tide tables, this is very easily understood. Now, we will be discussing about tides in the abnormality tide tables. I will be only discussing about the standard ports. This is an NP-205, this is the index of the standard ports. So, let us take Port Dickson. Port Dickson is on page number 33, it is the port in Malaysia, so we will go to page number 33. Always remember the tide, where they are taking the tide, they are giving you the lat-long. Next comes the time zones, Malaysia is at minus 8, so it is given here. Why this is given is, there might be daylight saving hours for a country. So, if you want to know what the daylight saving hours for the country you are sailing into is, you should refer ALRS volume 2. In volume 2, under legal times, the time zone as well as the daylight saving hours, starting date and ending dates are given. So, suppose there is a minus 1 daylight saving hour, so this local time will change to 0119. Remember all the tide table timings are given in local time. Next comes the neap and spring tides. All neap tides are at times when the moon is waxing or waning and this will be when the moon is at 90 degrees to the earth. The full moon and the no moon, this is a new moon and the full moon, full moon will come around 14 days, this is a full moon, will be periods of spring tide. I have explained to you how neap and spring occurs, so this is how it is going to happen and in this you can get an idea of whether the moon is waxing or waning by just finding out the whole black dot is showing there is no moon, then slowly it is going to full moon and at that time the moon is going to wax, that means it is adding up. This is how the tide is going to slowly come from neap, spring to neap and then to spring. Basically when it is a full moon, this will be the spring high and this will be the spring high for no moon. After that, the secondary ports I will explain in a later video. I hope you understood how to find out tides and how to calculate any daylight saving hours and the position. All this you will need if you are going to watch the video about tidal diamonds I had earlier uploaded. I hope you understood. Thank you.