Eagle Electronics SeaFinder 250 DF User Manual

Page 23

To choose the proper location for shoot-thru-hull mounting, follow these

testing procedures. You may need a helper to complete these steps.
1. Anchor the boat in about 30 feet of water. Add a little water to the

sump of the boat. Plug the transducer into the sonar unit, turn it on,

then hold the transducer over the side of the boat in the water. Adjust

the sensitivity and range controls until a second bottom echo is seen on

the display.
You will need to turn off Auto Sensitivity, Auto Depth Range and
ASP

. Try a range setting that is two to three times the water depth.

The harder (more rocky) the bottom, the easier it will be to get a second

bottom signal. Do not touch the controls once they have been set.

Example of a second bottom signal. Unit is in 30 feet of water, with

range set at 80 feet and sensitivity set to 87 percent

2. Next, take the transducer out of the water and place it in the water

in the sump of the boat, face down. Notice how the signal strength de-

creases. The second bottom signal will probably disappear and the bot-

tom signal intensity will likely decrease.

True bottom

Manual range setting

Second bottom