Heavy weather ballast tanks are designated onboard vessels and if those tanks carried oil previously they must be crude oil washed before carrying heavy weather ballast in them. Heavy weather ballast provides additional stability to the vessel and by lowering the centre of gravity makes the vessel more stable as the GM* increases. A vessel can thus take heavy weather ballast while or before proceeding to rough weather areas. Damage stability conditions to be evaluated carefully before the beginning of a voyage as it will assure compliance with damage stability requirements. It is advisable to keep at least 250 miles away from the centre of a storm however some companies prescribe specific distances in their Safety Management Manuals.Ĭheck Stability Of The Vessel: A prudent check is required on the stability condition of the vessel and its compliance with intact stability criteria. Buys Ballot’s law states – Face the wind and centre of low pressure will be from 90 degrees to 135 degrees on your right hand in N hemisphere and on your left hand in S hemisphere. It is vital to establish the distance of the vessel from it, the location of the eye of the storm, the centre of the depression, and storm’s track and path. Keep Away From Centre of Storm: Once the presence of a storm or depression is confirmed. Frequent observations from various meteorological instruments and prevailing weather onboard can be used to confirm weather reports. Thus a careful selection of Nav Areas and type of weather reports by the navigating officer can be instrumental in obtaining early warning about a storm. Study Weather Report: Often weather report and weather fax give warnings well in advance about unsettled weather conditions. Thus if prior information is available regarding the legs of a voyage where the rough weather is expected a sheltered passage or alternate route can be carefully planned to divert the vessel timely when required. A mariner has access to information regarding seasonal areas and frequency of occurrence through Maritime Safety information via EGC, Admiralty Sailing Directions, Ocean passages of the world and several other means. Use Available Information: Tropical storms and depressions are formed by pressure and temperature variations. It is therefore very important for a mariner to predict the location, magnitude and path of the storm, which is required to avoid these regions or navigate with caution while in navigating these areas.įollowing are a few precautions which seafarers must follow while encountering tropical storms or navigating in areas of their frequent occurrence. Tropical storms recurve after following a particular track*. ![]() A depression may often develop and travel in any direction whereas tropical storms are mostly found to follow predicted path* in both the hemispheres. Tropical depressions occur often in middle latitudes and tropical cyclones that originate in the Inter Tropical Convergence Zone. ![]() Movement of the sun causes pressure belts to shift and thus varying temperatures over land masses and water bodies cause pressure differences. Some of the most common forms of heavy or rough weather are tropical depressions or storms, typhoons, cyclones, hurricanes etc, generated due to varying atmospheric pressures over different parts of the earth.īeaufort wind scale criteria classify strong winds as near gale, gale, strong gale, storm, violent storm and hurricane based on ascending magnitude of wind force. Rough weather situation has been faced at least once or more by every seafarer during the course of his/her career. The prime reason for which every seafarer is wished “Smooth sailing and Calm seas” before boarding a vessel is to keep them safe from storms.
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