Inside the trials: testing S-100 aboard Stena Vinga

For S-100 to deliver its potential benefits, the data and systems that support it will need to prove they can work reliably and consistently together on the bridge.

That means taking testing beyond the office and the simulator and out onto working vessels.

The trial brought together hydrographic expertise, technology development and, crucially, the experience of the mariners using the information at sea. Water-level and surface-current modelling supplied by TideTech also contributed to the testing.

The objective was not simply to demonstrate new technology. It was to learn how S-100 information behaves in practice, how different data layers work together and how they can support the decisions mariners make on the bridge.

Captain Johan Karlsson, Master of the Stena Vinga, described St Helier as one of the most difficult ports he has navigated. The approach combines strong currents and changing depths with a tidal range of up to 11 metres and a confined harbour. Johan describes the challenge from a mariner’s perspective: “It’s a very small, confined space…the vessel almost doesn't fit inside”.

That makes understanding what the water is doing especially important.

During the trial, the bridge team was able to explore how different S-100 datasets could contribute to that picture or their ‘mental model,’ including S-101 Electronic Navigational Charts (ENCs), S-102 Bathymetric Surfaces, S-104 Water Level Information and S-111 Surface Currents. These were among the products supported by the S-100 ECDIS used during the trial.

For Johan, one of the potential benefits is being able to see information that previously required greater interpretation and calculation.

Johan observed that current and water-level information can be particularly useful when approaching confined ports like St Helier, or when navigating somewhere less familiar. His feedback points towards one of the broader lessons emerging from S-100 testing: the value of individual data products depends on the navigational situation in which they are used.

Tom Mellor, Head of Technical Partnerships at the UKHO, explained that with traditional S-57 ENCs, the available depth contours can mean areas of water appear to fall outside a vessel's selected safety contour, even where the bridge team's tidal calculations indicate there is sufficient water to navigate. Combining the higher-resolution bathymetry available through S-102 with water-level information has the potential to provide a more representative picture of the navigable water available to the vessel at a particular time.

For Johan, the wider opportunity is not simply having more information available, but using it to understand how the situation is developing. He described the potential for greater confidence, situational awareness and better “near-future planning”, by looking two or three minutes ahead as the vessel approaches the port.

This is also where the relationship between S-100 data and ECDIS design becomes important.

Andy Murray, Director of Navigation Solutions at Teledyne Raymarine Commercial, explained that much of the underlying information mariners need is already available today. The crucial difference is how much work may be required to bring it together.

S-100 creates the potential for more of that information to be integrated into the navigational environment. But, as Andy emphasised during the trial, simply layering more information onto a display is not enough. Mariners need to be able to access what is relevant when they need it, without having to navigate through unnecessary complexity.

Johan described the potential result in similarly practical terms: information that can help a mariner “visualise the situation before it occurs”, rather than simply reacting as conditions develop.

That potential depends on something more fundamental: trust.

One of the strongest lessons from the trial was that reducing workload is not simply a question of digitising more information. Mariners need confidence in the data being presented. Andy explained what S-100 seeks to avoid:

This is what makes operational testing so important. Testing aboard Stena Vinga identified areas requiring further investigation and refinement across both the data and its presentation. These included the coverage of high-resolution bathymetry, the portrayal of different information on the ECDIS and the accuracy and granularity of tidal and current information.

Finding those issues in testing is part of the purpose of a trial.

Tom explained that operating at sea has revealed characteristics in the data that were not apparent when it was being examined in an office environment. Those findings give data producers and technology manufacturers evidence they can use to improve the overall user experience.

The trial also reinforced the importance of having data at an appropriate level of detail for the environment in which it will be used. At St Helier, for example, the technical assessment identified a need to explore more granular tidal information extending further into the port to demonstrate the full potential of S-100 water-level information.

It is an important distinction. The benefits of S-100 depend not only on what the standards make possible, but on the quality, coverage, consistency and suitability of the data that ultimately supports them.

One example involved showing the crew different models for tidal information and asking for their assessment. Tom described the interaction as particularly valuable because it allowed the team to draw on the Master's operational expertise when considering which approaches could be most useful in future.

That feedback has a wider destination too.

Tom explained that lessons from trials such as this will inform the UKHO’s S-100 product development while also being taken back into the International Hydrographic Organization to support the continuing development of S-100.

Teledyne Raymarine Commercial described the same iterative process from the system manufacturer's perspective. Andy framed S-100 development as a “continual evolution”, in which direct access to mariners, data producers and hydrographic organisations helps identify not only what works, but what needs refinement.

This was the fourth live trial of UKHO S-100 data using the Teledyne Raymarine Commercial system aboard Stena Vinga. Each iteration has provided another opportunity to test data and functionality in an operational environment and feed what is learned into subsequent development.

The latest trial has also highlighted where further work can go next. Actions identified include engaging with ports to understand the data available for future S-100 products, exploring access to more detailed tidal information and improving the completeness and presentation of datasets used in testing.

For Andy, that continued process is fundamental to building confidence:

That may be one of the most important lessons from Stena Vinga.

Preparing for S-100 is not about proving everything in a single demonstration. It is about putting emerging data and technology into increasingly realistic situations, finding out what works and what does not and involving the people who will ultimately depend on it.

By testing, learning and refining together, hydrographic offices, technology providers and mariners can help turn the possibilities offered by S-100 into information that works where it matters most: on the bridge.

Discover how the UKHO and its partners are testing S-100 data and technology with mariners in live operational and simulated navigational environments.