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For the purpose of declaring drafts to terminal, charter, pilot and any other authority always draft at marks are given. draft at perpendicular are always used for CALCULATION purposes only.

Parallel Indexing are a series of parallel lines and a feature provided on the Radar screen (or PPI). PI is a tool which is used to enhance safe navigation in coastal waters. These series of parallel line aids in monitoring the vessel's passage and ensures that vessel passes at a safe distance from the navigational hazards. PI is used extensively during coastal navigation and requires radar conspicuous objects to operate.

Through MARPOL annex VI the IMO focuses on reducing the carbon emissions “globally” This was the prime intention behind making ANNEX VI mandatory( as a part of Marpol) The process was further accelerated by introducing a sulphur cap in 2020 which aims to further reduce the emissions at a global level and not local level. The idea behind not including the annex vi in PWC is that IMO decides not only on the basis of environmental considerations but also the commercial viability The other reason is the density of traffic in polar waters which is very less compared to the other parts of the planet which impacts the global warming issue predominantly. The other reason is the availability of optimum resources in polar water reasons including the current designs of engines and machinery. I am sure member states wont let it happen soon Having said that IMO is still figuring out the possibility of cleaner fuels which impacts the environment globally than locally. The decisions at IMO are also subjected to widely conducted scientific research. The issue of ‘black smoke’ in polar waters is a bigger challenge than anything else currently The work is under progress on that. Also Read this : Why long by chron method is preferred over Intercept method for morning sight?

Following are the reasons why the long by chron method is preferred over Intercept method during morning sight - 1. Long by chron method takes lesser time 2. Calculations are easier 3. For obtaining the noon position, the plotting is not required as the dlong can be calculated directly from the formula d'long = c corrn x d' lat Also read this : What are Temporary and Preliminary Notices?

T & P Notices also called as Temporary and Preliminary Notices, are provided in Weekly Notices to Mariners in Section II. These are shown with suffix (T) or (P) after each Notice Number. Temporary Notice may be issued to inform the mariner of any navigation affecting changes which are temporary in nature. Such eg may include - naval exercise, drilling activities, dredging etc. Preliminary Notices are issued to promulgate navigationally significant data to mariner when - 1. Action or work will shortly be taking place. 2. Information has been received but is too complex to be promulgated by chart updating notice 3. Further confirmation of details is needed. A chart updating Notice will be promulgated or New Edition issued when the details have been confirmed 4. For an ongoing and changeable situation such as a bridge under construction Also read this - What is a Wheel over point?

Wheel-over point is a point where the rudder is put over while considering the distance to the new course and the ship's turning characteristics. For a safe turn, it is necessary for a vessel to determine her wheel-over position or point. Also read this - What are different types of sailings involved in navigation?

Great Circle Sailing : shortest distance measured along the earth's surface between two places is called the Great Circle Distance. The departure and arrival positions are marked on a Gnomonic Chart and joined by a straight line. Waypoints are transferred from Gnomonic to Mercator chart and it appears as a Curved line on Mercator chart. Mercator Sailing : Used to find the Rhumb Line course and distance between two positions. It uses the following formula - tan Course = dLong / DMP This holds good when the distance is more than 600 NM. For distances lesser than 600 NM, we use Parallel sailing. The formula is given by - Cos mLat = dep / dLong Rhumb Line: Rhumb Line is a line drawn on a Mercator Chart which cuts all meridian at same angles. Composite Sailing: Sometimes, it is not possible to execute a full great circle for a voyage. This could be due to presence of navigational dangers in between OR if the Master decides not to go beyond a certain latitude owing to weather conditions. In this case, a combination of rhumb line and great circle sailing. Together this type of sailing is called as Composite Sailing. Also read this What is the difference between AIS A and AIS B?

AIS type A is mandatory for vessels 300GT and above and Cargo ships 500GT and above engaged on International voyages and all Passenger Ships irrespective of ships. AIS type B has a limited functionality and is intended for Non-SOLAS vessels. It is non-mandated by IMO. Class B is nearly identical to Class A except Class B does not transmit the vessel's IMO number, ETA or destination, navigational status, rate of turn information, sending safety messages (only receive), maximum present static draft and it also has a reporting rate less than Class A. Also read this - Why amplitude of moon cannot be taken?

The amplitude of any celestial body is taken, when the centre of the celestial body is at the rational horizon. In the case of moon, when it's centre is at the rational horizon, the moon is not visible on the horizon. Also read this - When is the best time to obtain the amplitude?

The best time to take amplitude is when the body is theoretically rising or setting. This means when the sun's lower limb is half the Semi Diameter above the visible horizon. At this time, the centre of the body is at the rational horizon, but the body is seen above the visible horizon because of refraction. Also read this - What is Spring tide, Neap tide, Flood tide and Ebb tide?

Tides are long-period waves that roll around the planet as the ocean is "pulled" back and forth by the gravitational pull of the moon and the sun as these bodies interact with the Earth in their monthly and yearly orbits. During full or new moons—which occur when the Earth, sun, and moon are nearly in alignment—average tidal ranges are slightly larger. This occurs twice each month. The moon appears new (dark) when it is directly between the Earth and the sun. The moon appears full when the Earth is between the moon and the sun. In both cases, the gravitational pull of the sun is "added" to the gravitational pull of the moon on Earth, causing the oceans to bulge a bit more than usual. This means that high tides are a little higher and low tides are a little lower than average. These are called spring tides, a common historical term that has nothing to do with the season of spring. Rather, the term is derived from the concept of the tide "springing forth." Spring tides occur twice each lunar month all year long, without regard to the season. Seven days after a spring tide, the sun and moon are at right angles to each other. When this happens, the bulge of the ocean caused by the sun partially cancels out the bulge of the ocean caused by the moon. This produces moderate tides known as neap tides, meaning that high tides are a little lower and low tides are a little higher than average. Neap tides occur during the first and third quarter moon, when the moon appears "half full." Whenever the change of tide occur from low tide to high tide at a given place , the tide is said to be flooding. During the period when the water level recedes from high tide to low tide, the tide is said to be ebbing. Also read this - What is the difference between the DR (Dead Reckoning), EP (Estimated position) and OP (Observed Position)?

Dead Reckoning position: After a fix is obtained, the next position of the vessel which is found by applying course steered, leeway and engine speed ONLY is called Dead Reckoning position. This is denoted by the symbol 'X'. Estimated Position: If the DR position (obtained above) is adjusted for prevailing set and expected drift then the position is said to be Estimated Position. This is denoted by the triangle symbol. Observed position or FIX: The actual position of the ship is called as the Observed Position or Fix. This is denoted by a Circle. The OP or Fix is the most accurate position of the ship. Also read this - What all factors affect the squat of vessel?

Following factors affect the squat of the vessel - 1. Speed of the vessel 2. Block Coefficient 3. Blockage factor 4. UKC of the vessel 5. Trim of the vessel 6. Location of the vessel (open seas or canal / channel) Also read this - What all correctors installed in magnetic compass?

Hi everyone.i watched your video tutorial on youtube.it is very helpful. Can I ask you to give me an excel sheet for trimming ?. Thank you so much