OpenSeaMap – the Free The biggest worldwide geodatabase, made by the crowd

Nautical charts are expensive, and in many countries data are not always up to date. OpenSeaMap is an alternative solution which is free for anybody to use worldwide. Following the example of , the data are collected by volunteers and are visible on the chart within just a few minutes. OpenSeaMap involves experienced mariners, programmers and thousands of data collectors, all of whom are working to produce a nautical chart with comprehensive, relevant and up-to-date data for water sports which is open to everyone and free of charge.

OpenSeaMap – the free shows details of the harbour, the 3. Aerial photographs with partly nautical chart – covers oceans ­infrastructure of various places, ­traffic excellent resolution obtained from and inland waterways worldwide. routes and much more. The river Bing, , local authorities ­OpenSeaMap works like Wikipedia, chart shows inland waters includ- and organisations are rendered the up-to-date, competent and most ing inland waterways as well as wild- manually into vector data of spatial comprehensive encyclopaedia in the water stretches for kayakers. information. Markus Bärlocher, world. Thousands of skippers, divers, initiator OpenData culture OpenSeaMap kayakers, and other water-sports OpenSeaMap is part of enthusiasts compile information they ­OpenStreetMap. The collection of OpenData means all databases that, in consider important and useful for free spatial data works just the same. the interest of the public, can be freely a nautical chart and save them in a There are three sources of data: accessed. OpenData is intended to ini- ­spatial database. 1. One million amateur cartogra- tiate developments that are ­profitable phers collect spatial data using GPS for the overall economy: by giving eve- Making use of , devices, at home and abroad. They rybody access, open data can be used ­OpenSeaMap is: update the with these data to create synergies and thus innova- • Up to date – every change is visible with a very keen eye for detail. tive products and ­services. It is crucial online immediately 2. Authorities and organisations that that the information can be re-used, • Specialised – every user enters data are increasingly embracing the worked with and propagated freely that they consider important idea of OpenData provide data by everyone. Spatial­ information is • Precise and detailed – continuously voluntarily. required to become OpenData as well. optimised by thousands of people • Comprehensive – information for everyone involved in water sports. Figure 1: Diving spots. OpenSeaMap is the fastest chart in . Items such as buoys that have been moved, a new harbour or the harbour master’s new telephone number can be found online within just a few minutes, instead of one year later in the next edition of a common harbour pilot book.

Oceans, rivers and topography OpenSeaMap is versatile. It contains­ information on oceans, rivers and topography. The chart does not end at the coastline but instead also

28 | march 2013 | Hydro international Figure 2: Offline charts in various formats.

The spatial data relevant for and descriptions of these objects are that it is necessary to modify these ­OpenSeaMap are virtual data such fine-tuned iteratively using nautical ­navigation programs so that they can as details of protection zones, data know-how and local knowledge. handle vector charts instead. ­relating to what lies beneath the water’s surface or concerning objects A user-friendly graphical editor All-in-one workplace far out at sea. Capturing these data is can be used to enter more detailed Leisure-sailing skippers need a not as easy as collecting data about descriptions. It was specially devel- ­modern, integrated system; instead of the countryside. The information is oped for nautical data so that water- using dozens of charts and manuals, already there but most nations treat sports objects can be depicted that the information must be contained it rather proprietarily. The OpenData are not usually included on tradi- in one single chart. This has already community hopes that the Open- tional nautical charts. The editor been realised on the web-based Data culture will increasingly spread translates the collected object details ­full-screen chart. amongst marine authorities. For into a data schema according to IHO example, OpenSeaMap is allowed S-57 and S-100. The data are then Selecting the menu option ‘View’ to use water level information and saved in a central spatial database. ­provides access to a wealth of infor- tidal information from , mation depicted in layers on the base ­, and Switzerland. Germany in Finally, the chart is rendered from the map. The ‘navigational aids’ layer con- ­particular shares quite a lot of coun- entered data and made available both tains typical features of a nautical try-specific data, and the German through the and as an chart. It has 18 zoom levels that range Bundesamt für Seeschifffahrt und offline chart. from a view of the world to detailed Hydrographie (BSH) has also offered harbour plans in 1:2000 scale. The to share quite significant data. Offline charts most advantageous combinations of Offline charts are available for use en objects are depicted for each partic- Collecting data route. They can currently be loaded ular zoom level. The ‘harbour’ layer Anyone can collect spatial data: ama- onto iPad or Garmin Plotter. As yet, shows 6,000 harbours, thousands teur cartographers and water -sports there is no application for Android of marinas, and anchorages. Click- enthusiasts as well as nautical and and OpenSeaMap is still looking for ing on the symbol opens the harbour­ bathymetry specialists, geographers Android developers. OpenSeaMap pilot which can be updated by users and hydraulic engineers. All objects offers hundreds of offline charts for with detailed descriptions and images relevant for nautical purposes that download from the website. of the harbours. The ‘weather’ layer are described in the international IHO comprises weather of the world standards INT-1, S-57 and S-100 can Vector charts are the future because including parameters such as wind be entered. There is simply no limit to they support head-up and true direction and wind force, air pres- the variety of objects. OpenSeaMap motion view. OpenSeaMap already sure, temperature, precipitation and shows anything from complex sec- provides vector charts for use on the height of waves. Also included tor lights and traffic separation areas Garmin devices. However, most of is a three-day weather forecast. The to shops for yachting equipment and the navigational software programs ‘water depth’ layer shows the deep- bakeries. The exact forms, positions still work with raster charts, meaning water bathymetry by GEBCO. The

Hydro international | march 2013 | 29 ‘ship tracking’ layer shows the AIS ­positions in real time. The ‘water Figure 3: European gauge’ layer shows dynamic water harbours. levels of coasts and rivers. The ‘aerial photograph’ layer was provided by Bing. The aerial photographs can be used to receive spatial data by digitis- ing them. The ‘Wikipedia’ layer has direct links to 2.5 million Wikipedia articles. This co-operation between OpenSeaMap and Wikipedia is aimed at benefiting from synergy effects and hence making a cultural contribution.

Of course, it is intended that all these layers will soon be available on offline charts too, so that skippers can check and monitor all nautical data and the onboard instruments via their Added value for organisations obtain from countries. That is why ­smartphone or tablet computer from In addition to skippers and water OpenSeaMap wants to measure the anywhere on the ship. sports enthusiasts, OpenSeaMap seacoasts worldwide using crowd- is increasingly being used by com- sourcing. In this way, everybody can Chart for water-sports enthusiasts munities and tourist organisations contribute and collect depth data. OpenSeaMap is interested in every- that want to offer a great service to Most ships are equipped with GPS thing that is ‘blue’ in the world – from guests and tourists. Thanks to the free and sonar systems, which makes oceans to rivers and streams; after license, any organisations can easily­ data collection easy. The devices can all, 70% of our planet’s surface is cov- integrate OpenSeaMap into their write the data via an NMEA string ered in water. Until now, users of the website free of charge. format. An NMEA data logger, which navigational charts have usually been was developed specifically for Open- skippers and motorboat operators. The same goes for commercial use SeaMap, then stores the data on a However, growing numbers of divers, for ship owners, charter companies, USB stick. Contributors can transfer surfers, kayakers, anglers and other organisations for the protection of the the collected data from any compu- water-sports enthusiasts are keen to environment, oceanologists, schools ter with internet access to the central benefit from OpenSeaMap too, and and universities. Furthermore, server. The raw data can be corrected they are catered for by the ‘sports’ users can add layers of their own (fed with heel and tide data) and layer. Among other things, this shows such as images of protection zones, ­calculated to create a terrain model. great diving spots, diving schools and ­construction projects, wind turbines, From this, depth contours will be places for filling up or renting scuba distribution of fish species or other derived and shown in the chart. tanks. Kayaking routes are marked information. with different colours depending on TeamSurv and ARGUS recently their degree of difficulty, and entry Shallow water depths explained in Hydro international and exit points plus obstacles and A chart without water depths is that finding contributors for crowd- spots where kayaks need to be carried rather useless, but unfortunately sourcing is quite a challenge. The are clearly indicated. depth information is difficult to OpenSeaMap community is large and spread all over the world, so the chances of this ambitious project succeeding are rather good. How- Figure 4: GEBCO water depths in ever, there are other challenges such the Street of as feeding the system with tide and Gibraltar. wave information data. It is therefore important to have bathymetry spe- cialists contributing to OpenSeaMap. And of course it would be especially valuable to benefit from the experi- ence of TeamSurv and ARGUS.

Our practical tests so far have proved quite successful. Extensive data col- lection will be starting in the sailing season 2013; however, any bathymetry already collected can be submitted to OpenSeaMap immediately.

Hydro international | march 2013 | 31 hardware, microcontroller, web pro- gramming, app programming, graph- Figure 5: Gauges in ics, web design, data transformation, real time. statistics, geodesy, bathymetry, ­, translations and more. Let’s build the chart together!

Acknowledgements Many thanks to all our diligent ­amateur cartographers and of course our programmers. Together, they all help to create OpenSeaMap.

The Authors Markus Bärlocher is an experienced skipper and sailing instructor. He is the initiator of OpenSeaMap. He sails worldwide and crossed the Atlantic Ocean W-E. Professionally he is an organisation developer. For OpenSeaMap, he Current challenge models, waves, wave travel times, ship had to learn a lot about bathymetry, cartography You can help us by telling people movements, etc. Professors and stu- and computing, and he is grateful to all the experts involved for their helpful conversations. about this project and asking your dents alike can find exciting topics for project@.org friends to update the chart with diploma theses or internship reports. ­spatial information about their place of residence or home country. Tell There are many more ideas for the people at your sailing club about ­OpenSeaMap and together we OpenSeaMap. Ask skippers to record can accomplish them. If you are a http://openseamap.org/ water depths and upload them. developer, you are welcome to join http://map.openseamap.org/ Researchers and scientists can help OpenSeaMap – we could use your map/ OpenSeaMap feed the system with experience in various fields such http://depth.openseamap.org/ depth data. We are looking for tide as servers, databases, rendering,

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