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TARGET SIZE
Body ............................................................... 5 m. (16 ft) ............................................... 10 m. (32 ft)
Lobster trap .................................................... 5 m. (16 ft) ............................................... 10 m. (32 ft)
55 gal drum ................................................... 10 m. (32 ft) ............................................... 25 m. (80 ft)
2 ft channel buoy and mooring ...................... 50 m. (160 ft) ............................................ 75 m (245 ft)
12 ft aluminum canoe ................................... 50 m. (160 ft) ............................................ 75 m (245 ft)
Large Prop (6' dia) ......................................... 50 m. (160 ft) ............................................ 75 m (245 ft)
Large anchor ................................................. 50 m. (160 ft) ............................................ 75 m (245 ft)
17 ft boat ...................................................... 75 m. (245 ft) ........................................... 100 m (320 ft)
30 ft boat .................................................... 100 m. (320 ft) ......................................... 200 m. (650 ft)
Small plane ................................................. 100 m. (320 ft) ......................................... 200 m. (650 ft)
Helicopter ................................................... 100 m. (320 ft) ......................................... 200 m. (650 ft)
Small barge ................................................ 200 m. (650 ft) ........................................... 300 m (975 ft)
Tugboat ...................................................... 200 m. (650 ft) ........................................... 300 m (975 ft)
75 ft boat .................................................... 200 m. (650 ft) ........................................... 300 m (975 ft)
Submarine (WWll) ....................................... 200 m. (650 ft) ........................................... 300 m (975 ft)
Destroyer .................................................... 300 m. (975 ft) ......................................... 400 m (1300 ft)
Battleship ................................................... 400 m. (1300 ft) ....................................... 500 m (1625 ft)
Queen Mary ................................................ 500 m. (1625 ft) ....................................... 600 m (1950 ft)
• Recommended boat speed of 1-3 kts for above chart.
• The distance shown is for one transducer.
• To determine actual swath coverage multiply range times two.
• The same chart is used for 100 or 600Khz, but the maximum range for 600Khz is about 75 m.
The above chart shows the recommended Range settings for different size targets when doing a general search. Once
a target is detected, the Range setting would be reduced and closer passes to the target would be made and at different
angles. The closer passes, at shorter Range settings, produce the best pictures. More detail is shown on the computer
screen when operating in the short ranges.
The above recommended ranges are conservative. A 75' boat (recommended range 200 m) could be picked-up at 300
m. But if you were on the 300 m range, and the boat was being seen from an end view, and the boat was laying on its
side, it is very possible that the resultant image would not be recognizable as a boat.
CHART EXAMPLE:
If the target you are looking for is similar in size to a 30 ft boat, you would search in the 100 m range (or less). Each
pass would cover a 200 m (1,300 ft) swath. Once an area is covered, it is recommended that it be recovered at a 90 deg
angle to the first set of passes. This is to insure the target is not missed due to poor target orientation on the first set
of passes. Once the target is picked-up, the Range should be set to 50 m. The search boat would make passes
approximately 25 m from the target. The target would be printed in the center of the screen for the appropriate channel.
The passes should be made at different angles in an attempt to get the best image. All passes must be made in a straight
line to insure printout is not distorted.
DETECTION RANGE CHART
RECOMMENDED
NORMAL
"RANGE"
SETTING FOR SEARCHING
(you can always a use shorter range)
7
RECOMMENDED
MAXIMUM
"RANGE"
SETTING FOR SEARCHING
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