Echo Sounder Operational Features

The echo sounder measured depth is displayed in:

Important

When changing the primary echo sounder (for example, if the current sensor fails), verify the correction settings in the Echo Settings window. Corrections may differ between sensors depending on the transducer installation location.

Echogram (Echo)

When an echo sounder is added to ECDIS, the ECHO tab will appear in the multifunction window.

Echogram

No.

Element

Description

1

Scale drop-down list

Changes the echogram scale.
Echogram scale

2

Drop-down list

Sets the depth reference line displayed on the echogram. Options: Waterline — depth from waterline; Transducer — depth from echo sounder transducer; Keel — depth under keel.
Depth reference line
Depth recalculation is performed based on the values entered in the echo sounder settings in ECDIS

3

Settings

Go to settings for depth monitoring

4

Echogram scale

In meters (units of measurement)

5

Echogram

Graphical depth display

6

Current depth value

Current depth with corrections applied

7

Time stamp

The point in time at which the depth was measured

8

Dangerous isobath

Entered in vessel dimensions

9

Time marks

On the echogram

10

Water temperature

Received from the echo sounder, in degrees Celsius. Received from sentence: $--MTW

Note

The echogram displays data in real time and allows visual assessment of the seabed topography beneath the vessel and the trend of its change. It is recommended to regularly review the echogram to monitor abrupt depth changes, especially when navigating in waters with numerous navigational hazards and in shallow waters.

Important

When interpreting echo sounder data, remember that the readings reflect the depth from the established reference point.

The reference line is set by the navigator independently, depending on prevailing circumstances: use Keel for monitoring under-keel clearance, use Waterline for comparison with the chart.

Warning

The echo sounder measures depth at the current moment in time. When the vessel is moving at high speed or in heavy sea conditions, echo sounder data may have delays or inaccuracies. Consider the dynamics of vessel movement and compare echo sounder readings with ENC data.

The echogram displays 15 minutes of echo sounder operation. To view previous depth values on the echogram — press and hold the left mouse button (touch and hold) on the chart and move the cursor (finger) to the right.

To return to current readings: left-click (tap) the current time stamp indicator.

Tip

For more effective use of the echogram, it is recommended to set the echogram scale considering the expected depths on the upcoming route segment. This improves chart readability and provides better assessment of the seabed topography.

Echo Sounder Transducer Settings

Go to Echo Settings:

Menu path

Menu → Settings → Echo Settings

Echo → Echo Settings

Echo sounder correction settings. Selection of the echo sounder transducer sentence for correct depth calculation.

The echo sounder can simultaneously transmit sentences $--DBT and $--DPT. After configuring the depth sensor, the NMEA sentence and the transducer position on the vessel hull must be configured.

Settings with $--DBT Sentence

Echo sounder settings

Settings with $--DPT Sentence

Echo sounder settings

When entering correction parameters, the following equality must be satisfied:

\[\Delta Z_{T} + \Delta Z_{K} = \text{Draught}_{WL}\]

where:

  • \(\Delta Z_{T}\) — transducer offset from waterline

  • \(\Delta Z_{K}\) — transducer offset from keel (element 6)

  • \(\text{Draught}_{WL}\) — vessel draught at the design waterline

If the equality is not satisfied, a message appears at the bottom of the window.

No.

Element

Description

1

Active echo sounder

Primary echo sounder name

2

Echo sounder data

Data values from sentences transmitted by the active echo sounder

3

For calculation use this sentence (drop-down list)

Selection of the sentence ($--DBT or $--DPT) whose data will be used for depth calculations

4

Calculated depth

Depth value calculated with the entered corrections

5

Transducer offset from WL

Set in the range from 0 to 29.9 m, default 0. Constant value for a fixed echo sounder. The equality \(\Delta Z_{T} + \Delta Z_{K} = \text{Draught}_{WL}\) must be satisfied

6

Transducer offset from keel

Set in the range from 0 to 29.9 m, default 0. Constant value for a fixed echo sounder. The equality \(\Delta Z_{T} + \Delta Z_{K} = \text{Draught}_{WL}\) must be satisfied

7

Depth from transducer (DPT)

Measured depth value from transducer to bottom

8

DPT Offset +

Distance from transducer to keel

9

Echo scale

Echo sounder operating scale. Transmitted only in the $--DPT sentence

10

Water temperature

Water temperature. Transmitted only in the $--MTW sentence

11

Depth from surface

Calculated depth from the water surface

12

Depth from transducer

Depth from the echo sounder transducer

13

Clearance (Depth from keel)

Calculated depth under keel

Warning

Echo sounder correction values affect all depth and under-keel clearance calculations in ECDIS. An error in correction settings may result in underestimation or overestimation of depth, creating a direct threat to navigation safety. Always verify that the equality \(\Delta Z_{T} + \Delta Z_{K} = \text{Draught}_{WL}\) is satisfied and compare readings with cartographic data.

Echo Sounder Warnings

TEXT

CATEGORY

CONDITION

Echo sounder sensor malfunction <sensor name>

Alarm

When data from the sensor stops being received according to the configurable timeout.

Check depth <sensor name>

Warning

The measured under-keel clearance from the echo sounder is less than or equal to the check depth value set in the settings (element 4 of the “Alerts” table).

Dangerous under-keel clearance <sensor name>

Warning

The measured under-keel clearance is less than or equal to the sum of the minimum under-keel clearance from vessel dimensions (section 6.2) and the value from the “Approaching under-keel clearance” field (element 2 of the “Alerts” table).

Minimum under-keel clearance <sensor name>

Alarm

The measured under-keel clearance is less than or equal to the under-keel clearance value set in vessel dimensions.

Depth less than dangerous isobath: <sensor name>

Alarm

The measured total depth is less than or equal to the dangerous isobath value set in the settings.

Echo Sounder Usage Recommendations

Important

The echo sounder is an auxiliary navigation tool and should be used in combination with other sources of depth information: ENC, visual observation. Do not rely solely on echo sounder readings when making decisions.

Warning

Echo sounder readings may be distorted under the following conditions:

  • High vessel speed (measurement inertia)

  • Heavy sea conditions

  • Presence of seaweed, soft bottom, gas bubbles in the water column

  • Low water temperature (possible changes in sound speed)

  • Improper transducer operation due to fouling or mechanical damage