Settings / Bathymetry (Only SEAiq Pilot)
Bathymetry is the study of underwater depth. The settings here affect how underwater features are displayed. Note that other settings, such as the Safety Depth, Safety Contour, Shallow Contour and Deep Contour also affect display of underwater features.
Use these features with care! Incorrect use can result in confusing display of depth related information. If you are unsure about the correct use of these features, leave the settings at their default values.
- Show bENC Overlays: (Only SEAiq Pilot) Enables display of Bathymetric overlays (bENCS). See detailed information below.
- Hide Unsurveyed Area Features in bENCs: (Only SEAiq Pilot) When enabled, causes Unsurveyed Area (UNSARE) features to not be displayed in bENC overlays. This allows features from an underlying ENC to be shown. Note that in some situations this can mix ENC and bENC features in ways where the boundaries are hard to distinguish.
- Show IHO S-102 bENCs: (Only SEAiq Pilot) When enabled, IHO S-102 bENCs will be displayed.
- Style: (Only SEAiq Pilot) When enabled, IHO S-102 bENCs are shown as raster.
- Raster Style: (Only SEAiq Pilot) When enabled, color will used for S-102 bENCs.
- Contour Intervals: (Only SEAiq Pilot) Set contour interval for S-102 bENCs.
- Precise Mariner Contours: (Only SEAiq Pilot) When enabled, contour lines for precise value of Safety Contour, Shallow Contour, and Deep are added to the display. This ensures that the coloring of depth areas is precise. However, this also means that there may be more contours than otherwise indicated by the differences in depth.
- Align to Safety Contour: (Only SEAiq Pilot) When enabled, contours are all aligned to the safety contour. If the Safety Contour is 6.75m and the contour interval is 1m then all contours will be X.75m.
- Smooth Contours: (Only SEAiq Pilot) When enabled, contour lines will be smoothed to create more realistic view of the contour lines. This necessarily causes the lines are moved up to one grid contour from their location in the data file.
- Tidal Adjustment: Provide adjustment to depths based on current tides. See below for more information.
- Fill Tidal Adjustment: This allows you to fill based on currently selected tide adjustment. Requires that you have selected an object with tidal data.
- Tidal Adjustment Warning: (Only SEAiq Pilot) When enabled and tidal adjustment is active, a large warning is shown in the lower center of the display. It is shown in addition to similar warning the lower-right (which is always displayed). The large display is only shown if the display size is large enough.
Safety Depth & Contour
- Draft: (Only SEAiq Pilot) Manual setting for draft of the vessel. This can be used to help configure Safety Depth and Safety Contour.
- Under Keel Clearance: Here you can specify how much additional UKC you want to use. The UKC can be given either as a fixed depth or a percentage of the vessel's draft. For instance, in some locations, it is common practice to use 10% of a vessel's draft as UKC.
- Shallow Contour Delta: (Only SEAiq Pilot) When set, this is subtracted from Safety Contour to set the Shallow Contour.
- Deep Contour Delta: (Only SEAiq Pilot) When set, this is added to Safety Contour to set the Deep Contour.
- Calculated Depth & Contour Settings: This is the calculated Shallow Contour, Safety Depth, Safety Contour, and Deep Contour, based on the draft, UKC, and deltas.
- Current Depth & Contour Settings: This shows the current value(s) for the Shallow Contour, Safety Depth, Safety Contour, and Deep Contour These are the same as given on the Vector Charts settings. When values are equal, they are elided.
- Update Chart Settings: Press this button to change current Shallow Contour, Safety Depth, Safety Contour, and Deep Contours values to the calculated ones.
- Automatic Update: (Only SEAiq Pilot) When enabled, the Shallow Contour, Safety Depth, Safety Contour, and Deep Contours are updated automatically when Own-Ship draft is changed. Additionally, the current Safety Contour is always shown in the bottom-right of the chart display.
In situations where tidal height is important to navigation the mariner may find it useful to adjust display of bathymetric features to account for the current tide.
This feature works both with and without bENCs.
The default setting is 0, which causes all bathymetric information to be displayed unmodified. This value may be changed to positive or negative values. Whatever value is selected will be added to the depth in the chart. If this is set to 10m, then a 15.3m sounding will be changed in the display to 25.3m.
Since depth information are typically reference a low tide datum, you will normally use positive adjustments that correspond to a higher tidal state. A situation where a negative adjustment would make sense is an extreme low tide.
After changing the setting, SEAiq will proceed to update any chart you display, in order to reflect the adjustment. There may be some delay as the chart is re-processed.
If you are unsure about use of this feature, leave it set to the default value of 0.
- When enabled, you will see (Tidal Adjustment) in the bottom-right corner of the display.
- If you ever want to change back to the default, just edit this setting back to the original default of 0 (no adjustment).
- All other depth related display information is updated accordingly, including Shallow, Safety, and Deep Contours. Soundings are reprocessed to account for the new effective Safety Depth.
- When Sounding Range and Tidal Adjustment are both used, then the Tidal Adjustment is applied to a sounding before determining if the sounding should be displayed. Changing the Tidal Adjustment may affect what soundings are displayed.
- This feature must be used with care. Tides are always changing. The setting you used an hour ago is likely no longer accurate.
- This is a static setting. SEAiq does not attempt to dynamically track tidal changes. If you want to change it further because tidal height has changed, you must do so manually.
- This setting is global in effect. Through correct use may cause display of bathymetric information in one area to be more accurate. However, display of information in most other locations is likely to be less accurate.
- It is up to the mariner to check the vertical datum to determine the correct reference datum to use when setting the adjustment.
- Only depth related features are affected by this setting. Any shore features (such as the height of lights) are not affected.
- When interrogating meta-data information using "Details for this Location", the meta-data is displayed unmodified (no tidal adjustment).
Safety Depth / Contour
The following settings are used to update the values of the Safety Depth and Safety Contour chart display settings. This feature is used to simplify calculations for the Safety Depth and Safety Contour settings. It is always possible to set the values directly by going to the Vector Charts settings and editing the values there.
Before using these settings, you should normally ensure the dimensions for Own-Ship have been set in the Own-Ship settings, in particular the Draft.
Display Bathymetric ENCs (bENCs)
In some area of navigation where detailed depth information is required for safe navigation, special digital charts called Bathymetric ENCs (bENCs) have been created. bENCs contain detailed information about depth not available in the normal charts for these areas. The bENCs are specialized in that they only contain bathymetric information and do not include other navigation information such as aids to navigation or bridges. Getting the full picture of both the bathymetric information and navigation requires displaying information from both bENCs and the corresponding ENCs.
When this setting is enabled, SEAiq modifies display of standard ENCs to replace underwater features (such as depth soundings, underwater contours, underwater depth areas, and dredged areas) with data from a bENC chart. Note that ENC navigation features are layered above bENC so that items such as buoys remain visible.
Use this feature with care. In some situations it can be confusing. If you are uncertain about the accuracy of the display, we recommend disabling this feature.
Below are some further notes/caveats:
- When enabled, you will see (bENC Enabled) in the bottom-right corner of the display.
- Enabling and disabling the feature will trigger SEAiq to reprocess the charts. There may be a delay while this happens.
- bENCs must not overlap each other, even if they have different compilation scale. In fact, the bENC charts (if there is more than one loaded) should normally all be at the same compilation scale.