Preparing the passage plan

 

 

The procedures for passage planning are given in Marine Manual Chapter 01.

 

 

During the passage planning process that you must check and confirm that all of the electronic charts loaded onto the ECDIS, and which are going to be needed during the voyage, are official.

Any sections of the passage plan for which official charts are not loaded, must be clearly identified. It should be noted alongside the appropriate waypoints where the unofficial chart will be in use, along with an instruction that an official paper chart must be the primary method of navigation during that stage of the voyage.

 

 

You can easily add or remove waypoints on a selected route. Most ECDIS will allow you to store up to

999 waypoints, and should enable you to make notes alongside each of them.

 

 

With the appropriate software programs and other necessary equipment, ECDIS can be programmed with information on vessel's status, performance and ability to perform manoeuvers. It can also take into account information on the cargo weight, the vessel's engine data, speed, rates of acceleration, stopping characteristics and turning circle. All these can be used to help plan and monitor the vessel's passage. Much of this information should already have been programmed into your ECDIS. Check it is still there and is still accurate.

 

 

Once you have completed your passage plan on the ECDIS you should save it to disk and name it with an appropriate title; you can then call it up again as the ship either clears the berth and gets underway or when you reach open seas. When completed, you must print out a paper hard copy of the plan and keep it as a back-up in case the ECDIS later develops a fault. This print-out should be signed by all the Navigating Officers after they have been familiarized with the passage plan.

 

Temporary and preliminary notices have not yet been fully integrated into ENC or RNC data by all National Hydrographic Offices. Caution must be exercised when navigating solely with ECDIS as some ENC or RNC data may not take account of temporary or preliminary notices.

The only guaranteed source for T&P information at present are Notices to Mariners (NM) issued by National Hydrographic Offices. The United Kingdom Hydrographic Office (UKHO) includes T&P notices within its ENC’s by including this information in its ‘Admiralty Information Overlay’. This tool allows the notices to be displayed as an overlay to the ENC in the Admiralty Vector Chart Service (AVCS),

 

 

The use of T&P NTM information is considered an essential part of keeping navigational charts up to date. Ships using ECDIS therefore have to take special caution while updating T&P NTM.

 

Depending on vessel’s route and ENCs used, it should be confirmed whether onboard ENCs include T&P NTM or not. If onboard ENCs do NOT include T&P NTM, manual means for correction of T&P NTM should be done through relevant NTM.

 

 

Navigational warnings transmitted by satellite communications (for example, SAT C telex), NAVTEX receiver and radio-broadcasted warnings are by nature more short term and urgent than temporary or preliminary notices. Navigators using ECDIS should be aware of the ability to plot new dangers on electronic charts through the use of the Marine Information Objects (MIO) capability. The purpose of the MIO is to highlight navigational warning information on the electronic chart.

 

Navigational warnings should be marked on the charts relevant to the voyage.

 

 

A p p r aisal and planning tips:

· Consider which electronic charts will be used for the passage, ENC or RNC data

· Check areas where RCDS mode will be operated, identify whether appropriate sets of paper charts are carried check local requirements of coastal states that may require carriage of additional publications or local charts

· Check that electronic charts have been updated to the most recent version and chart permit licences have been bought and being valid for the duration of the intended voyage.

· Route check previous passage plans after chart updating to ensure that any new dangers added don’t present a risk to the ship

· Modifications to the passage plan may be necessary to accommodate new chart features such as reporting schemes, traffic separation schemes (TSS), isolated dangers, etc.

· When planning new waypoints and courses, always use the largest scale possible so all features of the chart can be readily identified and risk assessed

· Ensure that the plan takes into account sufficient cross track error (XTE) to accommodate any deviations for collision avoidance or currents

· Ensure adequate values are inputted for safety contour and depth alarms

· Once the route has been planned, check the entire passage plan berth to berth on a 1:1 scale by manually scrolling along the track

 

 

· If the route has been planned in conjunction with paper charts, cross-check the distances between the paper chart and electronic passage plans to ensure consistency

· Check that tidal information is up to date and correct

· Check that the ETA has been updated

· Check that accurate draft details have been entered

· Squat details should be considered

· Make a back-up copy of the plan and save on a separate disk (usually USB stick)

· Most ECDIS units are provided with an automatic route safety check. If installed this must be used to verify the passage plan.

 

 

Safe planning

 

Always plan the route using both the ECDIS and its back-up system, and make sure the route is entered in both save the completed passage plan onto a disk, and also print out a paper copy make sure your ECDIS has received all the recent updates to keep its charts accurate. Use the largest scale electronic chart appropriate for all alarm indicators or for entering safety contours and prohibited areas. Remember, ENC alarms will operate automatically from the largest scale data, while data to trigger an alarm on an RNC has to be manually entered by the operator on the largest scale chart when entering waypoints on the preferred selected route into the ECDIS, also feed in a alternate route with alternate waypoints, specify a limit for deviation from the selected route, check if there are safety zones set up on the ECDIS, and whether they are still correct.

 

 

Route monitoring

 

ECDIS makes route monitoring very easy, but you must avoid relying entirely on it or radar as the only methods of safeguarding the vessel: it is important to always continue maintaining a regular look-out from the bridge. Always keep a navigation log on paper as well as the automatic ECDIS log. It is necessary to keep both the ECDIS and paper logs for at least one year.

 

The Master must specify at the outset of a voyage what standard information is needed to be on ready display on the ECDIS, such as chart orientation, range on display, safety zone and contour, he must also verify the same during route monitoring stage and verify that Watch keepers are aware of same.

 

Under special circumstances such as severe weather, if the Officer of the Watch wants additional information to be displayed for quick consultation, he can do so provided the display is set back to show standard information thereafter.

 

 

Adjusting a passage plan is easy as the voyage progresses. During route monitoring the ECDIS display will not only show the ship's position, but can also provide such information as the distance left or right of the intended track, time-to-run, distance-to-turn, position and time of 'wheel over', and past track history. Your ECDIS system should be able to keep a constant calculation of your passage, showing your ETA, required speed and elapsed time.

 

E xecution and monitoring tips:

• Check that the display has been set-up properly prior to sailing, otherwise important information may not be displayed

• Always operate ENC on the best scale possible to avoid crucial information being auto-filtered

and subsequently not being displayed

• Do not use ‘base display’ mode as this only displays the minimum amount of features and information

• Use ‘full display’ mode, but layers of information may need to be de-selected to avoid cluttering

the display with too much information

• Auto-filter or ‘SCAMIN’ may affect the display as it tends to remove information from the display if the best scale chart is not being used. Operators should know how to select the best scale chart to avoid the auto-filter feature removing information when using ENCs

• Ensure the GPS unit providing constant position fixing information to ECDIS has been updated with any relevant chart datum offset if the chart datum used in the raster chart is different from WGS (84). Failure to do so may result in positions being inaccurate

• Do not solely rely upon GPS position fixing when there are alternative position fixing facilities available. GPS is subject to a variety of different errors

• Traditional forms of position fixing should never be overlooked or replaced when using ECDIS;

these can include but are not limited to:

§ Visual bearings

§ Radar ranges and bearings using variable range markers (VRMs) and electronic bearing lines (EBL)

§ Transit bearings and clearing ranges

§ Running fixes

§ Fixing by a line of soundings

§ Horizontal sextant angles (HSAs)

§ Positions by celestial means (sextant)

• Make use of the Marine Information Objects (MIO) capability to plot electronically navigational warnings (e.g. NAVAREA warnings)

 

 

Safe monitoring

 

Whenever possible, have two electronic navigational systems in operation for establishing your vessel's position, set a generous time period for the ECDIS alarm to sound before your vessel crosses any safety boundary or begins to deviate from its planned route. When linked up with radar set a distance as per Master’s standing instructions for the ECDIS alarm to sound if another vessel approaches.

 

ECDIS usually offers the capability to overlay radar data onto the chart display. This may be selected targets or the full picture. According to the design, this option should be used frequently to verify the stabilization of the ECDIS image. Discrepancies between the radar image of a fixed object and its depiction as an electronic chart feature should be resolved by the “offset function” provided on the equipment.

 

 

The ECDIS must not be relied upon if the discrepancy between the radar display and the ECDIS

image persists, despite the use of the offset functions.

 

 

Target vectors, which are based on own ship’s speed through the water, will display incorrectly when overlaid on an electronic chart. Therefore when overlaying radar targets on an ECDIS display, the radar should be set to ‘ground-established’ (it follows that this should not be the radar used for collision avoidance).

 

 

Attention should be drawn to the following:

o Electronic Charts can be in vector or Raster chart format and the differences should be realized.

o The “look ahead” capability of raster charts is limited.

o When using raster charts, the automatic alarm features on the ECDIS system will not be triggered.

o If the equipment allows for radar targets to be overlaid onto the ECDIS output screen, it should

o be remembered; that the Radar will be set up to display targets allowing for ship’s log speed and not speed over the ground which the ECDIS will show.

 

 

The Master shall also ensure that navigation officers are aware of the potential dangers of over reliance on this equipment. The information from the ECDIS must not be over relied on as it is intended as an aid to navigation.

 

 

All on board involved in the navigation of the vessel must ensure the ECDIS must not be used as the primary means of navigation unless the vessel is equipped with two independent, certified ECDIS units. The means for primary navigation remains the largest scale paper charts appropriate to the navigation of the vessel which is being used to monitor the vessel’s passage and plot the vessel’s position at intervals specified in the passage plan.

 

 

Where information, such as the vessel’s position is obtained from ECDIS or equivalent, this must be cross referenced with an alternative and reliable source.

 

 

ECDIS provides instant monitoring of the vessel’s position in relation to the electronic Chart. As a cross check of this instant monitoring, during coastal and port passages Parallel Indexing (PI) should be used as a comparison and must be recorded.

 

 

Master must be informed in event of failure or problems with the ECDIS.

 

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