Docking Aids

SEAiq includes support for displaying extra data when docking vessels. This features are intended to be useful for large commercial vessels (100+ metres) with accurate Rate-of-Turn (ROT) sensor data. It is not intended for use with small recreational craft.

This feature attempts to provide as accurate of information as possible. In particular, it accounts for the location of the GPS antenna on the vessel and ROT, and their effects on the movement of different parts of the vessel.

When first using this feature, we recommend trying it with the Simulator to get a feel for how it works.

To use this feature, you will define one or more fenders. A fender may correspond to a wharf your vessel will be docking alongside or mark the boundaries of navigable areas.

As Own-Ship approaches fenders, fenders will automatically be selected for display, as described below.

For maneuvers such as approaching locks, you can set the Centerline flag in a fender. Then the information shown will help in aligning Own-Ship with the given centerline. Information for a centerlines is only shown when Own-Ship is at most 100m distance.

Settings

• Show Docking Aids : Enable to display docking information in the Navigate tab. For docking information to be displayed, you need to create fenders.
• Status : This displays the current status of Docking mode.
• List All Docking Fenders : This presents a table of all fenders.

Alternate Maneuvers

• Use VRMs as Single Point Mooring : When enabled (and Docking Aids are enabled), the closest VRM is treated as a single point mooring. The VRM must have a radius of at most 400m and its center must be within 1NM from the bow of Own-Ship.
• Use VRMs as Turning Circle : When enabled (and Docking Aids are enabled) and Own-Ship is near or inside a VRM, the VRM is treated as a turning circle. The bearing and range of Own-Ship center to VRM is displayed in a panel in the Status Bar. The Distance to outside of VRM is shown as though it were a fender. The VRM must have radius at length length of Own-Ship and at most 1000m and the center of Own-Ship must at most 1 ships-length outside the VRM for this to be activated.

• Use AIS Target as Docking Target (Only SEAiq Pilot) : When enabled (and Docking Aids are enabled), an AIS target can be used as a possible fender. The target is treated as though it had a fender beginning at the bow on nearest side to Own-Ship. It extends aft the length of the vessel and a further 0.5nm beyond the stern. This can be used as an aid when pulling alongside another vessel. The bow of the vessel is used as 0 mark to allow relative position of bow and stern to be determined.

  The vessel used for this is (1) the currently selected AIS target, or (2) the closest vessel at least the Small Vessel threshold for Meeting Points (Settings / Meeting Points / Small Vessel Length). Note that for (1), you can enable Settings / Status Bar / Lock Onto AIS Targets so that the AIS target is not lost when you select other items.

  You may find it helpful to use this with Settings / NMEA & AIS / Advanced / Interrogate Closest AIS Target in order to have faster updates for the target position.

  Important: Own-Ship and AIS target motion are incorporated into the estimate of closing speed with target. Rotational motion of AIS target (if available) is not used.

• Use Closest Vessel Tool as Docking Target (Only SEAiq Pilot) : Additionally, when this is enabled the closest Vessel Mariners Tool is used as a docking target. For this purpose, fenders are placed to position position Own-Ship over the target (not alongside). If a Vessel Tool is selected, then that takes precedence as the target.

• Use Safety Contour as Fender (Only SEAiq Pilot) : When enabled, safety contours and shore features are used as if they were fenders. Only charts with at least 1/30,000 compilation scale are used for these (unless Use Small Scale Charts for Fenders is on.

  When enabled, this feature may affect performance and battery life.

Options

• Use Fender Corners (Only SEAiq Pilot) : When enabled, docking mode shows distances to fender "corners" from points on Own-Ship. When disabled, distances to fenders are only shown when the closest point is not a corner. The default is to use corners.
• Inset Shoulder Points (Only SEAiq Pilot) : When enabled, shoulder points of vessel are 15% from bow/stern. The default is enabled. When disabled, shoulder points of vessel are corners of the "rectangle" indicated by the length and beam. Note that distances always treat the vessel as a rectangle, regardless of the shape drawn on the display.
• Only Show Distances : The default is to show distance, speed, and angle to the wharf. Enable this if you only want the distance to be shown.
• Use Speed Units (Only SEAiq Pilot) : The default for docking velocity is to use Settings / Units / Horizontal Units. Enable this to use Settings / Units / Speed Units instead.
• Prefer cm/s Instead of m/s (Only SEAiq Pilot) : Prefer cm/s instead of m/s. This only applies when Use Speed Units is not enabled and Horizontal Units is set to Metre.
• Use Small Scale Charts for Fenders (Only SEAiq Pilot) : When enabled, charts with as low as 1:100,000 compilation scale will be used for fenders.

Instructions

Here are the steps to setup and use Docking Aids:

• Set up NMEA/AIS and true-scale support for your vessel.
• Go to the Navigate tab and identify the wharf you intend to dock alongside.
• Create one or more fenders to identify the wharf you will be docking alongside or to mark boundaries of navigable areas. Single tap to mark one point of the fender, then double tap a second point, choose Add Tool, then choose Add Fender. You can select a fender, then graphicly adjust it or double tap another location and select Add Point to Fender. The new point will be inserted into the fender at the best location that can be determined.
• Turn Docking Mode on.
• When your vessel approaches the fenders, you should see the Docking Aids displayed as described below.

Display

The following docking aids are visible on the Navigate tab. Note that docking aids are only shown at display scale of at least 1:20,000.

• Additional predicted course lines are drawn as black dotted lines. These predict the movement of various points on the vessel, showing how it is moving over the next 6 minutes. The lines account for ROT. The points predicted are the bow, stern, and 4 shoulders (15% from bow/stern on either side). Predicted courses are only given if there is sufficient sideways movement away from the vessel.
• Minimum distances and velocity of change are given between key points on the vessel (bow, stern, 4 shoulders) and fenders. The lines for these distances are drawn as black dashed lines. The distance is given in metres. Velocity is given in metres/second unless you enable Use Speed Units, in which case the units normally shown for speed will be used. Positive speed means distance from fender is increasing; negative is decreasing.
• Information about the "wharf" that Own-Ship is approaching is displayed in the right hand status bar under Docking. The fender selected as the wharf is the closest fender less than 250m and with an angle to Own-Ship of at most 30°. If all fenders have an angle greater than 30° then the closest fender is shown.
• The interior angle between the vessel and the fender. This is always an angle between 0 and 90 degrees. This is only shown for the "wharf" fender (see above). It is only shown on the chart display when at most 100m from the wharf.

Creating Fenders from Charts

You can also create a new fender by extracting it from vector chart features. The advantage of this approach is that that (1) it is automatic, (2) the placement is based on chart features which (hopefully) have been carefully surveyed.

You can create a fender by double tapping on a wharf. Select Details for this Location. Then look for a Shore-line Construction feature and select that. Then select Add as Fender. This will create a new fender object placed along the wharf. You should double check that the fender placement is appropriate.

Some important caveats:

• This capability requires that IHO S-57 "Shore-line Construction" features are included in your chart.
• This feature only works on vector charts. In situations with matched raster and vector charts (such as NOAA charts for USA) where raster charts are preferred, you can try switching to the vector charts, creating any fenders you want, then switching back to the raster charts.
• Some chart features contain sequences of points that are all nearly in line with each other. When points are detected that are at most 2.5m from the being "in line" with adjacent points, those points are removed to avoid clutter.
• Some charts divide a wharf into multiple chart Shore-line Construction chart features. When this is detected, those features are coalesced into a single fender.

Single Point Mooring and Variable Range Markers

To aid in docking with a single point mooring (SPM), you can use a Variable Range Marker (VRM) to indicate the location where you are docking.

The following information is displayed in a block named Docking-SPM in the vertical status bar when docking to a SPM is enabled:

• The distance from Own-Ship's bow to the closest point of the VRM. If the bow is inside the VRM then OK is displayed.
• The velocity component of the bow in the direction of the closest point of the VRM. A negative velocity indicates the bow is approaching the VMR and a positive velocity means it is moving away.
• The angle between Own-Ship's centerline and the line from the bow to the closest point on the VRM.

Note that currently no information is displayed in the chart area.

The following conditions must be met for the SPM information to be displayed.

• The VRM must have a range of at most 500m.
• The VRM must have a fixed location or be attached to a waypoint. It cannot be attached to Own-Ship or to an AIS target.
• The distance from the bow to the center of the VRM must be at most 1nm.
• When more than one VRM meets these requirements, the closest to the bow is chosen.