International Hydrographie Review, Monaco, LXXVI(2), September 1999 [608458]

International Hydrographie Review, Monaco, LXXVI(2), September 1999
VOYAGE PLANNING IN ECDIS
by Hein SABELIS 1
This paper ivas first presented at the SASMEX Conference, 12-14 April
1999, Rotterdam, The Netherlands.
1. INTRODUCTION
The aim of this paper is to emphasize the need for a structured approach
to the development of tools for navigation support in ECDIS. To this purpose this
paper focuses on voyage planning in ECDIS, outlining a more formal approach, to
provide a basis for the development of tools for automated navigation support.
The outline of this paper is as follows:
First it will present some considerations regarding the development of
ECDIS functionality,
• then it will get into a definition of voyage p la n n in g ,
• followed by a conceptual framework of integrated navigation, which is
then used as
• the basis for a more detailed look into the voyage-planning process.
• This is followed by an impression of what could be envisaged as automated
support tools for voyage planning.
• Some concluding remarks are made in the final paragraph.
2. ECDIS AND NAVIGATION SUPPORT
The electronic chart development started with the sole purpose of
replacing the paper chart. Soon it was realised that the electronic chart functionality
1 Royal Netherlands Naval College, Department o f Nautical Sciences, Den Helder, The
Netherlands. E-mail: H.Sabelis@ kim.nl.

could be expanded to a navigation information system; the name changed from
electronic chart into electronic chart display and information system, ECDIS.
However, the term 'information system’ can still be interpreted as a system which is
simply able to display the stored data. In that case the discussion is reduced to the
selection of data to be stored, the data structure and the symbology or display
format. This basic interpretation does not lead to much added value. The added
value improves significantly when the system integrates the available data into
improved information products. This synergistic approach usually requires the data
to be structured into objects and attributes which can be used in processing
algorithms. The real value of ECDIS is determined by its synergism.
When designing support tools we tend to ask the practitioner what he
requires. Often however the practitioner is focused on the current procedures and
the workload involved. The result may easily be the development of a support tool
which in essence is an automated replica of the manual procedure, thus failing to
improve the solution because the underlying issue was not identified. Development
of support tools should therefore be based on a thorough analysis of the problem to
be solved. It should also be borne in mind that the tool should fit into the logical
process it is supposed to support, i.e. the tool should provide the required
information with the information available in that phase of the process.
The latest report of the workshop on development of Marine Information
Objects (MIO) for ECDIS [ECDIS/MIO] showed some of the aforementioned in the
resulting recommendations.
The point that is made here, however, is that the development of
navigation support tools for ECDIS is rather a result of individual ideas than the
results of a structured analysis of the navigation process It is the author’s view that
the development of new ECDIS functionality should be founded on some reference-
model of the navigation process, identifying logical structure and processes eligible
for automated support, possibly including agreed priorities. Manufacturers could
then focus their efforts to substantiate the identified functionality, standardisation
forums could concentrate on the required data structures, and data suppliers could
focus on providing the required data in the required structure in order of the agreed
priorities.
The next paragraphs will focus on voyage planning as an area eligible for
automated support by ECDIS.
3. VOYAGE PLANNING
3.1 Voyage Planning defined
Voyage planning can be defined as:
the systematic process in which a sailing order is translated into an
optimal navigation plan and detailed navigation scenario to fulfil the
mission, having considered all relevant information.

The sailing order may differ for the different user groups: transport,
fishery, offshore, navy, coastguard et cetera, but there will generally be a mission
element and a constraints element that are to be satisfied by the voyage plan. Often
the constraints are defined in terms of time, or economy, but they may also include
criteria such as ship’s motion or temperature constraints.
Voyage Planning is meant to provide:
• Prevention of potential conflicts or dangerous situations;
• Optimisation of planning for specific planning factors;
• A detailed scenario for the execution;
• A reference to compare the actual voyage progression with the planned
progression.
Typical of voyage planning is the great diversity of data to be collected,
consulted and integrated into both the overall voyage plan, and the detailed
navigation scenario for every watch.
3.2 Voyage Plan and Integrated Navigation
This paragraph aims to identify voyage planning in the context of an
integrated navigation system. Navigation can be defined as the process of
controlling the movement of a craft from one state (position, course, speed, etc.) to
another state, under predefined conditions.
Fig. – 1 : The Navigation Domain
From the perspective of elementary navigation disciplines (Fig. 1), this
definition encompasses a broad variety of subjects, ranging from positioning,
meteorology, tides, tidal stream, ocean current, hydrography and topography to anti­
collision regulations, communication and ship manoeuvring .

From the process perspective navigation is comprised of the
consecutive phases of planning, watch preparation, watch execution, and
evaluation.
There is also the system perspective where we can discern the
elements of data, algorithms, user-interface, procedures and the navigator.
With this cube-like model (Fig.1) of the navigation domain in mind we can
discern various sorts of system integration. First there is integration of different
navigation disciplines, which we could refer to as synergistic integration. Then there
is the integration across the various phases of the navigation process, where the
products of each navigation phase could be transferred to the next phases. In the
system dimension integration is concerned with the allocation of tasks to either the
system or the user, based on human factors methodology. In the data segment
integration is concerned with data models, data standards and data quality.
In view of the focus of this presentation I will not go into a detailed
discussion of integrated navigation. The remainder of this presentation will focus on
voyage planning, being the first two phases of the navigation process, across all the
disciplines and all segments of the system perspective.
3.3 Voyage Planning Process
The present standard for voyage planning is laid down in the IMO Guide
to the Planning and Conduct of passages. This standard discerns the phases of
Appraisal, Planning, Execution and Monitoring. Reading this document provides a
good impression of the factors to take into consideration. However, the document
does not provide' a clear picture of the logical structure of the process, the
interrelationships of the various aspects to consider, the questions to be answered,
and the products resulting from each phase. It is a listing of reminders and things-to-
do without logical structure or sequence. Therefore the document does not provide
a basis which is sufficient for the development of coherent automated support tools
for voyage planning.
Voyage planning is not a straightforward process which leads to the
correct answer. It is much more a search through a wide variety of, often time-
variant, information in many different publications. The navigator’s task is to identify
and comprehend the most important aspects to develop his voyage plan. In doing
so he is repeatedly revisiting these aspects at an increasing level of detail while at
the same time the voyage plan develops.

Fig. – 2: Voyage Planning Process
Voyage planning can be seen as an iterative cyclical process, (Fig.-2) as
represented by a spiral model, with a standard logical structure and a clearly defined
product for every cycle. Each product serves as a directive for the next cycle. The
first cycle, route planning, is concerned with selecting the best route; the product is
the route plan, an outline description of the route which is feasible within the
constraints provided in the sailing order.
The second cycle, navigation planning, is concerned with the question
how to navigate the selected route: the precise track to follow, the associated safety
margins, track deviation tolerances, the overall time schedule and the navigation
procedures for the different phases of the voyage (Fig.2).
The resulting navigation plan should provide guidance for every officer of
the watch to independently carry out his watch preparation resulting in a fully
detailed navigation scenario for his watch.
Theoretically speaking each cycle as aforementioned consists of the
consecutive phases of analysis, synthesis, decision, and direction for the next cycle.
The analysis-phase starts with the basic issues such as: what is required, within
which constraints, which information is required, what does that information indicate.
In the synthesis-phase options are generated and considered. Next the plan is
finalised in the decision-phase and worked out to the required detail in the direction
phase in order to serve as a reference directive for the next phase.
This formal description of the voyage planning process may seem very
theoretical to the navigation practitioner. However, the experienced navigator may
well recognise the ’ essential ingredients in the procedure he personally developed
over the years. This theoretical procedure is not meant to be formally implemented
in full detail in the daily navigation practice. It is meant to provide the basis for
development of automated tools to support the voyage planning process.

4. VOYAGE PLANNING SUPPORT OUTLINE
The following paragraphs provide an outline description of voyage
planning support as envisaged for ECDIS. It is based on the aforementioned
analysis. It is not meant to provide a complete picture. It is an extract, just to provide
an impression of the required functionality that would result from a proper analysis.
4.1 Cycle-1: Route planning
The aim here is to select the best route fulfilling the mission within the
constraints as prescribed. The system requests the ports of departure and arrival to
be identified on an overview map, including the basic planning constraints in terms
of ETD and ETA, speed characteristics and maximum draught, cargo class. The
system searches a predefined route network, to come up with an outline of
feasible route options. ‘Feasible’ in this stage indicates that the basic ship’s
constraints have been verified against the route constraints. Therefore the attributes
of each leg of the route network include the basic parameters of that leg, such as
distance, maximum allowable draught, speed limitations and prohibited cargo
classes. Attributes may also provide references to other limitations that should be
brought to the attention of the mariner on presenting the route as a feasible option.
Next the presented route options are verified against a climatologicl and
oceanographic database for critical and significant environmental factors as defined
by the operator in terms of wind-speed and -direction, seastate, ice, ocean
currents. Unfeasible route options (e.g. through ice) are then deleted and significant
environmental characteristics are assigned to the remaining route options. The
result is an overview of feasible route options with their specific characteristics in
terms of distance, time, economy, and environmental factors, providing the
necessary information to make an initial route selection. The result is a route
defined by Route points and connecting legs, with an associated bandwidth for
detailed track planning, together with an initial time-schedule and possibly some
pointers urging for more detailed planning, such as tidal time-slots.
4.2 Cycle 2: Navigation planning
The main questions to be answered in this cycle are concerning the
definition of navigation track, its subdivision into phases of navigation (e.g. ocean,
coastal, confined waters, inshore conditions), the associated safety margins and
cross-track tolerances, the associated navigation procedures, and the detailed
planning of critical elements of the voyage (e.g. tidal time-slots, critical passages,
etc.). Before the course lines are drawn the system should mark areas of unsafe
waterspace (within the defined route bandwidth). Then it highlights the vessel traffic
data along the route such as TSSs and recommended tracks and routes. With this
information the navigator can draw the initial course lines. Next, the system provides
an initial subdivision of the track into the standardised phases of navigation.
Assigning these phases of navigation automatically assigns specific (standardised)
navigation procedures (positioning procedures, manoeuvrability, bridge manning,

etc.) to each phase of the route. Then the track is tested for critical points, as
defined by the user, based on a combination of criteria such as safe water margin,
positioning accuracy, tidal stream and water depth, prompting the navigator to
adjust the track or to define additional measures and criteria in a decision point.
Then the system generates associated information regarding traffic
management (reporting point, procedures etc.), pilotage (procedures, positions etc.)
and communication, based on the fairways and traffic management regions that are
passed. The resulting Navigation plan provides all information for every officer of the
watch (OOW) to do the planning of his next watch in full detail.
4.3 Cycle-3: Watch preparation
The aim of this cycle is to produce a fuily detailed navigation scenario for
the next four to six hours
Upon starting his preparations the OOW will require a geographical
overview of the voyage with a small window indicating the area of interest for the
hours of his watch. From here the OOW will focus on the area within this window to
familiarise with details of the navigation plan for his watch. The system recalculates
the planned time schedule in case of any significant deviation from the route or time
schedule. This may also involve recalculation of tidal streams UKCs etc.. Now the
OOW will need to review the weather situation for his watch. To this purpose the
system provides a comprehensive graphical presentation of the weather situation,
based on actual data (own sensors), nowcast- and forecast-data, focused on: wind,
seastate, visibility and precipitation. The OOW draws conclusion on impact on
speed limitations, positioning options and collision avoidance. The next step is for
the OOW to plan every course alteration in full detail under the anticipated
circumstances of tidal stream, visibility and traffic.
Then the OOW attempts to picture the visual environment in terms of both
general and navigation specific characteristics. The system may provide support by
detailed pictures, annotated aerial overviews and possibly a video impression. This
information may be augmented by a textual description, which is kept to a minimum.
The navigation pian, together with the detailed complementary information
can be seen as the detailed navigation scenario in which the track and the
associated time schedule are leading for the actions to take, in terms of
manoeuvres, radio communication, ship’s procedures, navigation procedures and
decisions on feasibility.
Once again this description is far from complete, it is just an extract,
meant to provide a picture of logical structure derived from analysis of the
underlying process, resulting in options and requirements for automated support.

5. CONCLUDING REMARKS
Modelling the process to be supported provides a clear insight into the
logical sequence of questions to be answered, with the data available in the specific
phase of the process.
This can provide logic and structure into the supporting system, thus
inviting the user to follow a structured process, at the same time ensuring that all
relevant information is considered. A formal analysis of marine navigation and the
processes involved could serve as a reference for manufacturers, data managers,
researchers and regulators to provide coherence and purpose into the development
of ECDIS as an information system. It could also serve as a reference for the
customer to compare and contrast different systems.
Bibliography
IMO, International Maritime Organization; Guide to the Planning and Conduct of
Passages: IMO Circular SN/CIRC. 92; London, 23 October 1978.
IMO, International Maritime Organization; Performance Standards for Electronic
Chart Display and Information Systems (ECDIS); Resolution A 817(19) adopted
at the 19th session of the IMO general Assembly, London, 23 November 1995
STCW-95, Standards for Training Certification and Watchkeeping 1995; Voyage
Planning ; STCW Convention of 1995, Section A – VIII/2; London 1995.