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Assumptions shall not be made on the basis of scanty information

  • Rule(s) to be applied: Rule 7 (Risk of collision)
  • Applying the Rule(s) and comments: In accordance with Rule 7 (c) (Risk of collision), assumptions shall not be made on the basis of scanty information, especially scanty radar information.
    Explanation of scanty information:
    - Any conclusion based on simple observation of the radar without a plot is risky and unreliable. It is also a question of reliability of radar information when quality of radar bearing and range is poor and more reliable information must be gathered.
    - Scanty information depends on what information is presently available and how much more information can be assessed before an action can be taken. Scanty information is when an officer of the watch fails to determine accurately and with a satisfying degree of certainty whether there is a risk of collision. It is when the information is of poor quality and where more information must be gathered to determine the risk of collision. At times it may be very difficult to decide with certainty if there is a risk of collision. In such cases it is the best practice to assume that there is a risk, until it is proven otherwise.
    - In Rule 7 (c) it is used word "assumption", but in determining if risk of collision exists, it is dangerous to make assumptions. Actually, OOW have to make "conclusions" rather than assumptions.

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