Bushnell MARINE Manuel page 2

About The Ranging Reticle
There are vertical and horizontal lines on the reticle (Fig. ). Each minor division on both vertical and horizontal lines represents
5 mils and each major division represents 0 mils (one circularity angle=6400 mils. (one circular angle equals  degree of angle,
equals one minute of angle, equals 60 seconds of angle, and equals 6400 mils.)
How to use the reticle to measure azimuth:
Azimuth of a body is the arc of the horizon intercepted between the north or south point and the foot of the vertical circle passing
through the body. It is reckoned in degrees from either the north or south point clockwise entirely around the horizon. Azimuth of
a current is the direction toward which it is flowing, and is usually reckoned from the north point.
Fig. 1
Fig. 2
A mil's reticle can measure the azimuth angle, upper and lower angle, distance and size of an object or target. The visual distance
reticle lines can measure the distance of normal object easily on the basis that the object to be measured is at least  meters (6 feet)
in height.
How to measure the azimuth angle:
The azimuth angle is the angle included between two objects to be measured at the horizontal direction of the binocular. (or two
ends of one object at horizontal direction)
When the azimuth of two targets is smaller than the azimuth measuring range (-50~+50 mils) inside the binoculars, aim the scale
line at one end of the reticle at the target then read the value of the scale at which another target was located on the reticle. The
value is the measured azimuth mil. As shown in Fig. , the azimuth of the target (tank) is 0-0 mils. The azimuth between the
targets (p-p) is 0-80 mils.
When the azimuth of two targets is bigger than azimuth measuring range (-50~+50 mils) inside the binoculars, an area on the
targets can be selected to make the necessary estimated measurements in a step by step fashion. The sum of the value from each
step is used to obtain the measured azimuth. As shown in fig 3, the azimuth of target (cruiser) is 130 mils (60+70=130).
When the azimuth of a target is longer than the azimuth measuring range (-50~+50 mils) inside the binoculars, you can visually
calculate the total azimuth mils by using the vertical line on the reticle by placing the image in a position where the vertical line
splits the image. You will need to take two image readings. Mentally, consider the horizontal with three reference points. Point A
is the 50 mil point on the far left side. Point B is where the vertical line intersects the horizontal line. Point C is the far right 50 mil
point. Now your first reading on the image will be the mils from point A to B with point A on the far left part of the image.
(see Fig. 3). Your second reading will be from point C to point B where point B is now the spot on the image where point B ended
after the first reading. After calculating the mils for each image, you then can add them together to get the total azimuth reading.
In the (Fig. 3) image below, the ship is longer than the total 100 mils available on the reticle. However, by doing the foregoing mil
calculations, you can now obtain the ship's total mil azimuth of 130 mils ( 60 + 70 ).