| Why Nautical Charts are Essential. | | | | flow, every hour of the tidal cycle. |
| Navigation & Chart Plotting. | | | | Important points to keep in mind when you are reading |
| Many new boating people who are out in the sea do | | | | a nautical chart:o Make a thorough reading of the |
| not feel it's important to carry nautical charts on board. | | | | chart.o Carefully monitor your position, which you will |
| I must say that it is a risky habit. A nautical chart gives | | | | follow and pursue the course you will take.o The notes |
| you the relevant information required to make a safe | | | | and other indication such as obstructions, water depths |
| passage plan using the charted fixed marks such as | | | | indicate something so you need to be clear with |
| buoys and landmarks, so that you can take bearings | | | | them.o Make a note of whatever you observe on the |
| and maintain a correct course. | | | | nautical chart.o A careful monitoring of the chart will |
| Pilotage Information: With the help of the nautical chart, | | | | show you visual objects and you must be able to |
| you can gain pilotage information regarding the position | | | | identify with your position. |
| and nature that is favourable to the navigator. The | | | | The chart has a superimposed compass rose on it |
| nautical chart holds crucial information such as seabed | | | | that indicates true North and the magnetic correction |
| information, landmarks, and seamarks. There are | | | | required to your course to steer. |
| symbols that describe the seabed, such as the depth | | | | To make a fix on the chart i.e. mark where your boats |
| of the ocean, possible hazards, and tidal information. | | | | actual position is on the chart, this can be carried out |
| The charts also have symbols for lights, lighthouses, | | | | as follows; |
| buoys and land structures and features, which is very | | | | With the aid of a hand bearing compass, from the |
| essential for position fixing. | | | | boats deck, take three bearings of fixed objects on |
| Many charts also use colors to distinguish between | | | | the land or in the sea, as far apart within the 360 |
| manmade features. One has to be clear with the | | | | degree compass circle as possible. At the same time |
| charts to understand the indication in the nautical | | | | make a note of the boats 'log' (distance travelled |
| charts. The chart may indicate a seabed that lies | | | | through the water) the boats speed, the depth of |
| permanently below the water level or the seabed that | | | | water under the boat and the time. |
| becomes dry at low tide. There are various symbols | | | | Now on the chart table, identify the three fixed objects |
| to indicate water levels, but contour lines are shown to | | | | you have used to take your bearings from on the |
| identify changing depths. | | | | chart. Now draw a line in pencil on the chart of the |
| To understand the depth of the water: Numbers | | | | actual hand bearing compass readings from each |
| marked in the chart indicates mostly depths that have | | | | fixed object. The three lines you have drawn will |
| been measured. Most charts use meters to indicate | | | | converge forming a small triangle, your boats position is |
| the depths. However, the charts that are published by | | | | within that triangle. Mark next to that triangle the boats |
| the US Government use feet. Depth curve lines | | | | log reading taken and the time for reference, you can |
| indicate about the relief underwater. The differing | | | | then check the depth of water from the chart is the |
| colour portions in the sea mean that there is | | | | same as the depth taken when making the fix, this |
| obstruction underwater or indicates shallow water. | | | | helps to confirm your position. If the depth or your |
| Such points are only understood when one is aware | | | | three lines do not converge errors have been made |
| about importance of nautical charts and are familiar | | | | and you need to repeat the process again. |
| with the symbols and signs. | | | | Your new course can now be plotted from that new |
| To understand about tidal information: Nautical charts | | | | datum fix on the chart. |
| provide information on tidal movement. The strong | | | | Now days the use of GPS (Global Positioning |
| water currents and tidal races have special chart | | | | Systems) undertake the above process for you, but I |
| symbols. The nautical chart will carry tidal diamonds, | | | | am a great believer of knowing what to do if the lights |
| which indicate the bearing and the speed of the tidal | | | | go out! |