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REPORTING POSITION ANGLE
SCANNING PROCEDURES - 12018_110

Basic Military Requirements (BMR) - Requirement for military advancement
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inexperienced  lookout.  Distances  can  be  very deceptive. A  ship  that  looks  like  it’s  1/2  mile  away  may actually be twice, or more than twice, that distance from you. Sometimes objects that seem to be half the distance to the horizon may actually be considerably closer. Knowing your height above the water helps you to estimate ranges. For example, at a height of 50 feet, the distance to the horizon is about 16,000 yards (8 miles); at a height of 100 feet, the distance is about 23,000 yards (11 1/2 miles). Practice estimating distances to known objects.  Until  you  become  proficient  at  estimating ranges, use phrases, such as “close aboard,” “on the horizon,” and “hull down.” Ranges are reported in yards and spoken digit by digit, except that multiples of hundreds and thousands are spoken as such. USE OF BINOCULARS Using binoculars for searching isn’t always better than using the naked eye. Several factors govern when and how binoculars should be used. For example, in fog binoculars should not be used. At night, they should be used quite often. Another factor is their field of view, which is about 7°. Depending on the type of search, such a narrow field may hamper proper scanning techniques. Adjusting Binoculars Three adjustments are required to obtain proper focus  and  to  gain  maximum  benefit  from  the light-gathering quality of binoculars—two adjustments for  focus  and  one  for  the  proper  distance  between lenses. To properly focus your binoculars, you should do the following: 1.  Set both eyepieces to the +4 mark. Place the binoculars  firmly  against  the  eyebrows  and locate a small, well-defined object about 1/2 mile away. 2.  Cover one lens. (Do not touch the glass.) 3.  Slowly turn the other eyepiece until a sharp image  is  obtained,  then  back  off  as  far  as possible without losing the sharpness. (Keep both  eyes  open;  closing  one  will  give  an incorrect focus.) 4.  Note the reading on the scale; then repeat the previous procedures two or three times to obtain the exact setting. Follow the same procedure for the opposite eye. T h e   fi n a l   a d j u s t m e n t   i s   t o   e s t a b l i s h   t h e interpupillary  distance  (IPD),  which  is  the  distance between your eyes. Move the barrels up and down until you see a single circle (fig. 3-7). Then note the reading on the IPD vernier between the barrels. An incorrect IPD setting will strain the eyes and waste part of the binoculars’ light-gathering ability. You  won’t  have  your  own  personal  binoculars. They are passed from watch to watch. Therefore, it’s important for you know your focus and IPD settings so that the binoculars may be properly adjusted at night or when there are no objects on which to focus in the daytime. For nighttime use, the focus setting is one mark less than for daytime. Daytime use of binoculars depends upon the type of search being conducted. Surface lookouts should use them to scan across their sector—they should then use the naked eye on return sweeps. Sky lookouts should use them only to identify a contact detected with the naked eye. The binoculars should be used more frequently at night than during daylight, but searches should still be made with the naked eye. You often can see objects, particularly moving ones, out of the corner of your eye. These objects might not be detected with the binoculars because of their narrow field of view. Binoculars should never be used in fog, rain, snow, or thick haze. 3-16 Student Notes: Figure 3-7.—Proper IPD setting.







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