Tidal Stream Prediction Calculation using Admiralty Tide Table

Good afternoon, so this is basically the Singapore Strait So whenever you are transiting any straits Which is connected to a water body on Both sides there is going to be current So the current that is going to affect you will basically have a big effect on your ETA as well as for you to Transit any point that you have to transit within a specific period of time now This is Singapore chart number is 4041 chart number is 4041 and Indonesia this is the eastbound lane, and this is the westbound lane and This is the Batu Burundi light so Going to Admiralty tide tables. This is the admiralty tide tables in that admiralty tide table. There is a section for tidal streams so tidal streams This is the tidal stream prediction page This will give you the tidal stream for any locality That means they have some specific locations, this is the list of all the points they are going to give you details about So they will give you the tidal stream prediction for each day of the year for you to calculate tidal stream basically you should be having a graph paper and Most of the ships when they transit Singapore Strait or Malacca Strait They will be asking you to prepare this tidal stream graph so that we will get a general idea of how the current is going to be favorable or be adverse So now since we are going to discuss about Batu Burundi We will take the Batu Burundi page on the tidal stream calculation So you can see This is how it comes out So I'll explain it with Batu Burundi Too much This is Batu Burundi So suppose we are in the month of November November as you can see the page will give you first the time zone then The point this is Singapore Strait of Batu Burundi and they are going to give you the tidal stream predictions in knots For a position of this this is the lat long Latitude and longitude I can just show you on the chart and 1 degree 12 minutes north is this and 53 is this so basically they are going to give you the tidal stream prediction for this point and Then comes the directions it's very simple if The value is in positive. That means the direction of flow is two three eight and If it is negative the direction is zero five eight. This is basically 180 degree opposite so all the Dates will be given out Suppose we are for November the day it is going to give remember. This is the no moon full moon and The waxing or waning phase all this had Told you about in the tidal table calculation Video, so I'm not going to further explain it again then comes two timings one is Slack then next comes maximum and then there is a rate So the point when it is slack water means the speed is going to be zero When it is maximum Suppose it is 0 7 1 4 that means 0 7 1 4 The rate is 1.8 knots and since it is positive. The direction is 2 3 8 again This goes back to Slack time So in this day, there is no second slack coming Then the next time is 1 2 3 7. So I will give you an example in this it will give you a better understanding see 2 0 2 9 was the slack time then 0 0 0 4 The rate goes to minus 2.3 then it goes to 0 4 3 2 again a slack then 0 7 2 9 it goes to 1.7. That means it is going from minus 2.3 knots at 0 5 8 Direction to 0 at 0 then 1.7 in 238 direction at 0 7 2 9 so to Calculate it. I have already made a chart for us The title prediction will just have to draw a graph Take a middle of the graph as 0. This is 0 knots You can see I have written it 0 knots then Since test 0 knots then minus 0.5 1 1.5 to this is the speed and plus 0.5 1.0 1.5 to the side and This is the timing so whenever I am going to make a graph it will be a time of maximum rate Then comes the slack water Then the maximum rate in the opposite direction again a slack quarter again a maximum rate. So it will be in the form of curve so I will to Reduce the time period of this video. I'll just Record all the values and show you how it can be read out. So I'm just keeping it here so that you will get Idea of how it is made the graph you can see the graph speed hours and the direction now, let me Plot the timings and I'll explain it Now I have already prepared the chart. So I will be using the dates of December and In the month of December, I will be using the date of 15th December and 16th December why I am going to use it is it will be easier for me to show you everything now because there will be two rates and the same direction on the 15th it is 23440.5 Because it is positive. That means the direction is 238 then again on 116 there is no slack at first again. The rate is going to 2.3 at 0608 then goes down to 1012 at slack and Again go back to minus 2.4 that is in 058 direction at 1421. So If I show you this example, it will be very easy for you to understand. So I have already prepared that the graph All the timings you can see I've written it down this is 2344 of 15 Then comes 0608 of 16 then 1012 of 16 1421 of 16 Then goes back to slack at 1832 of 16 2154 of 16 it goes back to positive and 2356 again, it stays positive. There is no slack So as you can see in the graph, it is going from one direction It is increasing in the direction going to slack Then going to the opposite direction again going to slack Again going in the positive direction So once you prepare this graph how you are going to use it is suppose you are going to pass the Batu Barahandi say around 0500 so you have the timing on one side and the rate of The tidal stream on the other side. So you just have to Take a measurement using the graph at 0500 The direction of flow will be this so This will be 0500 0500 the direction will be since it is positive is 238 direction and the speed is going to be Two knots you can see two knots The graph will help to interpret the speed now again If it is in the evening six o'clock, no, sorry, we will take it as five o'clock in the evening at Five o'clock just see where the graph is meeting It is meeting here So the direction is negative negative means 0.058 That is the direction of flow 0.058 and the speed is less than one knots Maybe around 0.8 So 0.8 knots Will be the speed at five o'clock in 0.058 direction So 0.8 knots 0.058 direction at 1700 all this time Is given in local time that is the reason they have given you the time zone on top So whenever your ship is transiting this point if your time zone Ships time is at minus eight. That means this is going to be the local time at which The tidal stream is going to happen on that locality remember this Will give you a general idea on how your ship speed is going to increase or decrease or have no effect depending upon slack or maximum So your ETA can be adjusted accordingly Now of Bathu Bharganti, there is no current given if there is a current They will give it somewhere here. So I'll show you an example Okay Now, this is Singapore Strait Sailat Philip At Sailat Philip, you can see The current is nil It is even as nil that means there is no current that is going to affect the whole calculations So somewhere around Horsburgh Lighthouse. Yeah, so this is Horsburgh Lighthouse at Horsburgh Lighthouse current is not included in the predictions and it is nil to 0.3 knots direction 056 from April to November and 0.5 to 1 knots in a direction 236 from December to March that means this much You can expect the current also the stream direction 056 starts flowing north and turns east Stream in direction 236 starts flowing south and turns west. This is how the tidal stream Will change whenever there is a current so this they will give you at the bottom of the pages of the calculation. I Believe you got a good understanding of how to use admiralty tide tables for calculating tidal stream predictions Remember this admiralty tide table was covering only this much area so In different volumes, you will get tidal stream predictions for different points Thank you for watching