[. . . ] Always use your personal seafaring experience when interpreting the displayed values. Safety Instructions concerning the installation The system components should be installed by your shipyard or by a specialist. Remove all metallic or electrically conductive jewellery, such as chains, bracelets, rings, etc. Disconnect the minus polarity at the battery before starting work to prevent the risk of short-circuiting. [. . . ] If the alarm continues, although the connection is perfect, please contact your VDO agency. 32 BASIC CALIBRATION Basic calibration of the VDO Depth Sounder Selection of the unit Setting the keel depth Keep the pushbutton pressed and switch the indicating instrument power supply on. The current unit setting (feet in the example) is displayed. Push the button to toggle between the units feet and meter. About 5 seconds after unit selection the instrument prompts for the keel depth entry. The display shows , , OFFSET" and, shortly thereafter, the current keel depth setting (0. 0 in the example). os 0. 0 OFFSET = keel depth Push the button until the measured keel depth (1. 2 m in the example) is set. Incrementing is automatic if you keep the pushbutton pressed. os 1. 2 The setting range is 0. 0 to 3. 0 m or 0 to 9 feet. The set value is stored if the pushbutton is not pressed for 5 seconds. After a double acknowledgement tone the depth is displayed automati33 BASIC CALIBRATION / ALARM cally. The unit now displays the water depth below keel (4. 6 m in the example). --4. 6 Setting and activating the shallow water alarm In unsafe depths and in waters with unknown depths the alarm will warn you in time to avoid shallows and to prevent boat damages. The alarm can be switched off or on by double activation of the pushbutton when the display shows the current depth. The display shows the alarm threshold (0. 0 m in the example) when the alarm is switched on. Set the desired alarm threshold by pressing the pushbutton. Up to 10 m (32 feet) the value increments by 0. 1 m (1 foot), up to 120 m (396 feet) by 1. 0 m (3. . . 4 feet) per button activation. Continuous incrementation is obtained by keeping the pushbutton pressed. After about 5 seconds after setting of the alarm threshold (0. 9 m in the example) the display shows the current depth (2. 7 m in the example) , and the set value is stored. 2. 7 A continuous alarm is sounded if the depth below keel is less than the set alarm threshold (0. 9 m in the example), and the flashing display shows the current depth measurement (0. 7 m in the example). 0. 7 34 ALARM The acoustic alarm can be switched off by pressing the button. It stops automatically when the depth below keel is greater than the set threshold. The alarm function is deactivated if the button is quickly pushed twice when the current depth (2. 7 m in the example) is displayed. 2. 7 Push button Push button off 2. 7 35 TROUBLESHOOTING Troubleshooting Fault: - No depth sounder function Cause and correction: - Check electrical connections per wiring diagram. - Bad connection between sounder and display, Check the connections. - Wrong indication - Display shows three bars - Display shows The following causes may be the reason for a ground echo not being received or evaluated correctly: -The maximum measuring range of 120 m is exceeded. -Water layers of differring salt content or temperature, for instance in estuaries or sewage treatment plant outflows. -The water contains air caused by preceding ships or by backing your own boat. -Strong electromagnetic disturbances, for instance by refrigerator, motor, radio equipment, etc. [. . . ] Lock the retainer pin by installing the rings at both pin ends. Tie the control rope of the blind plug to one of the retainer pin rings. In this case the blind plug must be secured in the same way as the sounder. Please note that a considerable quantity of water can enter the ship while the sounder is being removed. [. . . ]