With the advent of electronic chart systems (ECS) on vessels of all sizes, there is now the possibility to use computer model output directly in the navigation system, so there is no longer a need to have the weather on a separate piece of paper. The computer model data is available in GRIB (GRIdded Binary) format and there are many ECS packages which are able to display, for example, wind speed and direction on a regular grid, directly on the navigation surface.

In order to find out to what extent this kind of functionality is being used, a web-based survey was carried out using a questionnaire to establish how mariners acquire and use weather information in UK coastal waters.

Responses from 464 mariners were received and by far the largest group of respondents came from the leisure sailing category - which is perhaps understandable as they are the mariners most dependent on weather conditions. In the subsequent analysis, the large and small vessels in each category have been grouped together, so that results are reported in the four categories: Commercial, Fishing, Leisure:Power and Leisure:Sail.

The methods by which weather information is obtained was recorded by vessel type. It is noticeable that VHF broadcasts, the Internet and public TV/radio are generally the most popular access methods. It is perhaps surprising that this medium features so strongly amongst commercial ships. Mobile phones and radiofax are used relatively little.

Some relevant facts about the operational profile of the responding vessel were also collected, including more detail on the weather information used. It is obvious that the Shipping Forecast and Inshore Waters Forecast from the Met Office are very well used. (The Met Office kindly created a link from the Shipping Forecast webpage to the survey and this clearly introduces a significant potential bias in the data. However an analysis of the responses received before this link became active verifies a usage figure of over 70% in all categories.)

The main focus of this work is to identify trends in the use of weather data in ECS and the analysis shows that the penetration of this technology is now around 30% in leisure sailing vessels and over 60% in fishing vessels. However, the ability to integrate weather data in ECS is at a very low level. The most likely types of vessel to carry this functionality are small commercial vessels and large leisure powerboats - but only around 20% of ECS-quipped vessels in these categories have weather and navigation integrated. The only other types of vessel that showed any appetite for such functionality were leisure sailing vessels and large fishing boats.

The survey also tested the attitude of mariners to various aspects of the weather services provided and it was found that most respondents, in all types of vessel, strongly agreed that good weather information was important for their operations. A large majority also agreed that the information that they receive is usually accurate, but there was only a small positive bias towards wanting more detail.

Two questions focused on the use of ECS and the integration of weather data. There was quite a large spread of opinion about whether such systems such be regarded as ‘standard equipment’, although there was a clear majority who held the view that it would be useful to display weather information in the ECS.

It is perhaps surprising that mariners still rely heavily on traditional products, such as the Shipping Forecast, when more modern sources of information are available which integrate with the new technology of ECS. The GRIB data that is available free on the internet (and at very low cost in compressed format from specialist suppliers) also potentially provides more detail than is possible by ‘traditional’ means. For example, the wind direction and speed in a Shipping Forecast area will typically be dealt with in less than 10 words. By contrast, plotting standard GRIB data over the same area will offer several different data points providing a more detailed prediction of the winds to be expected.

There are some technical barriers to delivering digital data to a mobile marine platform - but these are disappearing fast. There are also bandwidth limitations, but vessels receiving document-based forecast products on a digital data link are often using more bandwidth than would be required to send a superior GRIB product which could be displayed in the navigation system.

An example of standard 1º (60 miles) resolution data is shown to the right using the MaxSea package. Such data, with forecast values for up to three days ahead, can be loaded through an iridium phone for a pound or so.

Higher resolution model data provides an even more detailed picture of the weather and with this depth of information it is possible to observe the advance of frontal systems and identify small-scale features which might otherwise be overlooked.

Whilst such detailed data may be of little value to large commercial vessels making passage in normal circumstances, there are a range of scenarios where such functionality could prove invaluable. These include, port operations, search and rescue and other specialised vessels - such as fast ferries, salvage vessels etc.