International Journal

on Marine Navigation

and Safety of Sea Transportation

Volume 2

Number 3

September 2008

259

The Role of Operational Ocean Forecasting in

E-Navigation

J. Graff

BMT, Teddington, England, UK

ABSTRACT: Advances in ocean modelling have led to improved performance for operational ocean

forecasting and the availability of continuously reliable forecast information for certain ocean regions of the

world. Although such forecasts are being increasingly adopted into a wide range of services across the

maritime industry they have not yet been considered as candidates to supplement or to substitute conventional

tide tables for navigation use. The issue is important in the context of climate change and the added

uncertainty now placed on the use of conventional tide table for navigation in complex coastal waters. In the

context of e-navigation it is timely to begin to explore the issue and examine how such forecasts might be

used and adopted. This requires closer connectivity between ocean forecasting and navigation communities

and the involvement of overarching organisations such as IMO and I GOOS. This paper raises the issue and

opens the debate.

1 INTRODUCTION

Climate change driven by global temperature rise is

producing increasing variability of seasonal weather

and a marked increase in the frequency and severity

of storms. The consequential impact on the oceans is

significant, leading to global sea level rise, abnormal

coastal flooding and complex behaviour of tides and

currents in coastal waters. For navigation, especially

in coastal waters, weather forecasts are becoming

increasingly important and the need for a navigator

to estimate the deviation of true water levels and true

currents from those presented in official tide tables is

paramount. The accuracy of model generated ocean

forecasts has improved substantially over recent

years and operational services are becoming

increasingly available especially in context of

national flood tide warning, marine search and

rescue, port approaches and offshore operations.

Advances in satellite based internet broadband

directly enable web service delivery of data and

information which contributes to a new emerging

framework for e-navigation that offers possibility for

integrating operational ocean forecasts into onboard

ECDIS systems. This paper raises the concept of

adopting operational ocean forecasts as a formal

component of ECDIS and introduces some of the

main issues to be considered.

2 SEA LEVEL AND CLIMATE CHANGE

According to the forthcoming fourth IPCC report

(IPCC 2007 WG1 Release, 2007); “at continental,

regional and ocean basin scales, numerous long-term

changes in climate have been observed. These

include changes in arctic temperatures and ice,

widespread changes in precipitation amounts, ocean

salinity, wind patterns and aspects of extreme

weather including droughts, heavy precipitation, heat

waves and the intensity of tropical cyclones. Global

average sea level rose at an average rate of 1.8 [1.3

to 2.3] mm per year over 1961 to 2003. The rate was

faster over 1993 to 2003: about 3.1 [2.4 to 3.8] mm

260

per year. Whether the faster rate for 1993 to 2003

reflects decadal variability or an increase in the

longer-term trend is unclear. There is high

confidence that the rate of observed sea level rise

increased from the 19th to the 20th century. The

total 20th-century rise is estimated to be 0.17 [0.12

to 0.22] m.” The implication for the next century to

2100 suggests that tropical cyclone intensity and

extreme sea level frequency will increase and mean

sea level will rise 20 - 60 cm.

3 TIDE TABLES FOR NAVIGATION

The SOLAS 1974 Convention governing Safety of

Life at Sea provides a comprehensive set of

regulations made up of XII chapters. Chapter V –

Safety of Navigation; identifies certain navigation

safety services which should be provided by

Contracting Governments and sets forth provisions

of an operational nature applicable in general to all

ships on all voyages. This is in contrast to the

Convention as a whole, which only applies to certain

classes of ship engaged on international voyages.

Chapter V was updated in 2000 to take account of

new digital technologies and evolution of Electronic

Chart Data Information Systems ECDIS

developments.

SOLAS Ch V/1974 Regulation 20 pertaining to

Nautical Publications was revised and updated as

SOLAS Ch V/2000 Regulation 27: Nautical charts

and nautical publications, such as sailing directions,

lists of lights, notices to mariners, tide tables and all

other nautical publications necessary for the

intended voyage shall be adequate and up to date.

Regulation 27 is supplemented by an Annex 3:

Nautical Data and Publications which incorporates

Regulation 19.2.1.4 that specifically lists Tide

Tables and Tidal Stream Atlases as publications

required onboard.

Whereas the SOLAS Convention and its

Regulations come under the auspices of the

International Maritime Organisation IMO, the

governance of navigation charts and tide tables

comes under the auspices of the International

Hydrographic Organisation IHO with important

scientific input addressing mean sea level and tidal

monitoring contributed under the auspices of the

International Oceanographic Commission IOC.

Tide tables themselves are a responsibility of

individual countries that are required to ensure

adequate provision of information to ensure safety of

navigation in their national waters. The UK

Hydrograghic Office has traditionally provided a

global coverage of tide table data in addition to that

for UK waters only. Nowadays, most countries with

extensive coastlines have the capacity to produce

their own national tide tables with UK and USA

providing greater global coverage. However,

whereas tables providing tidal height predictions are

easily produced, increasingly accurate and readily

available, the same is not true for tidal stream atlases

which are still based on rudimentary tidal chart data

and increasingly outdated content of the important

Pilot publications.

Currently, the carriage and usage of tide table and

tidal stream atlas data by vessels for navigation

seems to be very varied with no overall governance

pertaining to use of best available data or guidance

as to its interpretation. National hydrographic

authorities such as USA, UK, Australia and New

Zealand are increasingly making their national tide

table predictions available freely over the internet

and other internet sites such as

www.mobilegeographics.com using XTide software

can now be found offering tide table predictions on

demand for almost any global locations. However, a

quick look at freely available predictions for the

same port from three different sources show

differences that suggests a need to address the

question of compatibility and compliance. In

congested coastal regions and major port approaches

pilotage is already being facilitated by access to real-

time readout from regional tide gauges or current

meters. In operational engineering environments

sensitive to sea state such as offshore construction or

large structure tow-out, the provision of numerical

model based sea level and current forecasts,

allowing for non-tidal effects, is already an

established requirement.

The increasing access to a widening range of tidal

predictions that may be used for navigation is a

situation that has to be recognised as a potential

problem and one that has to be addressed.

4 OPERATIONAL OCEANOGRAPHY

Advances in ocean modelling have led to radically

improved performance for operational ocean

forecasting and the availability of continuously

reliable forecast information of sea levels and

currents for certain ocean regions of the globe. In

Europe which is well served by its national

forecasting agencies work is advanced in moving

towards a unified approach for providing operational

ocean forecast coverage for regional European Seas

and Atlantic waters. Similar capacity exists amongst

national forecasting agencies in other parts of the

globe such as USA, China, Japan and Australia.

Although such ocean forecast data are being

increasingly adopted by industry to meet marine

operation needs ranging from search and rescue to

261

ship routing and tow-out they have not yet been

considered as candidates to supplement or to

substitute conventional tide tables for navigation.

Part of the reason may be to do with the complex

make-up and uncertain positioning of GOOS the

Global Ocean Observing System, which is a

permanent global system for observations, modelling

and analysis of marine and ocean variables to

support operational ocean services worldwide.

Connectivity between GOOS and IMO/IHO is

clearly lacking.

The intergovernmental IOC-WMO-UNEP

Committee for GOOS (I-GOOS) was initially

established by the IOC Executive Council at its

twenty-fifth Session (Paris, March 1992) as the IOC

Committee for GOOS (resolution EC-XXV.3), to,

inter alia, replace the Committee on Ocean

Processes and Climate. WMO and UNEP agreed to

co-sponsor the Committee in 1993.

GOOS is not an entity but is a platform for:

− International cooperation for sustained

observations of the oceans

− Generation of oceanographic products and

services

− Interaction between research, operational, and

user communities

GOOS is implemented by:

Member states via their government agencies,

navies and oceanographic research institutions

working together in a wide range of thematic panels

and regional alliances.

The complex structure of GOOS is illustrated in

Figure 1 below.

Fig. 1. Structure of GOOS from www.ioc-goos.org

The GOOS Project Office is the organizational

and coordination hub of GOOS. The office is hosted

within the IOC/UNESCO headquarters in Paris,

France and is funded by UNESCO/IOC, USA, UK,

UNEP and WMO.

The nature of GOOS implementation mechanism,

as highlighted above in italics, together with the dual

domain services vision responsibility, for coastal and

open oceans, as indicated in Figure 1, creates a

highly confusing picture with regard to figuring out -

how the national ocean forecast service providers

(mainly the Meteorological Offices) should be

connected with the IMO SOLAS navigation

requirements? In other words – how to create a

suitable IMO-I GOOS-IHO partnership that will help

to realise modern tidal navigation needs?

5 E-NAVIGATION

The IMO Maritime Safety Committee (MSC) at its

81st session in May 2006 decided to initiate a high

priority item on "Development of an e-navigation

strategy", with a target completion date of 2008. The

aim is to develop a strategic vision for e-navigation,

to integrate existing and new navigational tools, in

particular electronic tools, in an all-embracing

system that will contribute to enhanced navigational

safety while simultaneously reducing the burden on

the navigator. E-navigation would thus incorporate

new technologies in a structured way and ensure that

their use is compliant with the various navigational

communication technologies and services, such as

ECDIS, that are already available, providing an

overarching, accurate, secure and cost-effective

system with the potential to provide global coverage

for all ships.

E-navigation compliments the emergence of the

term Marine Electronic Highway MEH (Sekimizu et

al 2001, Gillespie 2005) and the initiation in 2006 of

a key MEH pilot demonstration project in the Straits

of Malacca and Singapore. The four-year regional

demonstration project aims to link shore-based marine

information and communication infrastructure with

the corresponding navigational and communication

facilities aboard transiting ships, while being also

capable of incorporating marine environmental

management systems. IMO state that “The overall

system - would also include positioning systems,

real-time navigational information like tidal and

current data, as well as providing meteorological and

oceanographic information …”

Development of an e-navigation strategy by IMO

is currently under active discussion with responses

now in place for reporting back to the IMO NAV53

meeting in July 2007. As of 20

April 2007 there are

OOPC

: Ocean Observing

Panel for Climate

JCOMM: Joint WMO-IOC

Technical Commission for

Oceanography and Marine

262

66 response documents posted on the IHO web site,

one of which; the IALA Definition and Vision for

E-Navigation, posted 29

March 2007 (IALA 2007)

presents a descriptive model for e-navigation that

clearly highlights inclusion of oceanographic predic-

tions as input for creating operational navigation

information in an e-navigation context. Key applica-

tions identified by IALA are route planning, under

keel clearance, berthing and SAR response. Bearing

in mind the important role played by IALA the

International Association of Marine Aids to

Navigation and Lighthouse Authorities in driving the

adoption of key technology applications such as

VTS Vessel Traffic Systems and AIS Automatic

Identification of Ships, its contribution highlighting

oceanographic predictions, ie., operational oceano-

graphy, should be treated with great seriousness and

should be considered as the opening to develop

inclusiveness of the GOOS community into the

e-navigation framework. It is noticeable that amongst

the 66 contributing responses on e-navigation posted

on the IHO web site that reflect world-wide

participation, I could not identify any representatives

of the GOOS community.

6 CONCLUSIONS

The maritime community is currently in the process

of establishing a strategy for adoption of e-navigation

as an enabling framework for integration of new

forms of technology and information to aid and

enhance safety of navigation world-wide. A key

component for safe navigation is the use of best

available tide and current predictions. In the context

of climate change and its impact on the seas it is

necessary to consider how operational ocean forecasts

might supplement or replace onboard tidal publica-

tions. The global ocean modelling and forecasting

community GOOS is advancing and improving

capacity to provide operational forecasts. Currently

the GOOS community and the maritime navigation

community are not closely connected; it is timely

that closer connectivity should be encouraged. The

following three recommendations are proposed.

1 In view of the increasing availability of tidal

predictions over the internet it seems necessary to

develop guidelines governing use of these data for

navigation.

2 Consideration should be given to the use of

operational ocean forecasts for navigation and a

strategy should be developed for their adoption

and use.

3 Formal cooperation between the maritime

navigation community represented by IMO, IHO

and IALA and the operational ocean forecasting

community represented by I GOOS should be

established as a matter of priority.

REFERENCES

Gillespie, R. 2005. Global Marine Electronic Highway:

proposed vision and architecture. Canadian GeoProject

Centre, 2005.

IALA 2007. The IALA Definition and Vision for E-Navigation.

e-NAV2-output 11, March 2007.

IPCC 2007. Contribution of Working Group I to the Fourth

Assessment Report of the Intergovernmental Panel on

Climate Change. Summary for Policymakers. April 2007.

Sekimizu, K., Sainlos, JC. & PAW, JN. 2001. The Marine

Electronic Highway in the Straits of Malacca and Singapore

– An innovative project for the management of highly

congested and confined waters. IMO, July 2001.

SOLAS 2004. SOLAS (2001 and 2002 AMENDMENTS)

IMO, London, ISBN 92-801-4183-X, 2004.