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RowingCAS—A Collision Avoidance System for Rowing

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RowingCAS—A Collision Avoidance System for Rowing

RowingCAS is a smartphone based Collision Avoidance System (CAS) for rowing and the water sports.

RowingCAS warns about dangerous approaches with swimmers, other boats or fixed obstacles like buoys, poles, bridge piers etc. Other boats and swimmers must be equipped with RowingCAS as well to enable warnings.

Please read this note about fixed obstacles.

It's dead-easy!

Install the app, launch it, and off you go! That's all you have to do to use it. There are no complicated configuration options.

Swimmers can stow their smartphone in swimming safety buoys.

RowingCAS requires a mobile data connection which is nowadays widely available on lakes or coastal areas.

While it was primarily designed for rowing, RowingCAS is also perfectly suitable for sailing, kayaking, small motor boats and yachts.


RowingCAS includes a live tracking function. Tracking can be enabled and disabled using the Settings menu.

How does it work?

Once per second, RowingCAS sends a position update to a tracking server. The server determines whether a collision risk exists with another RowingCAS device or a fixed obstacle. In this is case, an alarm tone sounds and the target symbol on the display changes color in accordance with the time to and distance at closest approach.

The algorithm is carefully designed to warn only if a collision risk actually exists.

Besides computing the collision risk, the server also sends back the position of the five closest targets within display range.

A note on fixed obstacles

Fixed obstacles are stored in a server-side database. They are shown as green circles on the tracking site (please zoom in on your area!). Because RowingCAS is so new, the map isn't complete yet. In order to complete it, we'd like to invite you to help us by contributing your obstacles. Your local knowledge is the best (and in fact, only) way to ensure good data quality.

Please contact us for write access to the obstacle map. Don't worry, the process is fast and efficient!

How much does it cost?

The passive beacon function of RowingCAS (e.g. for swimmers) is and will remain free. We do however plan to introduce a moderate fee for other functions like tracking, active collision warning service (i.e., radar + alarm tones) etc. in the future.

System requirements

RowingCAS supports Android and iPhone. It needs:
  • A mobile data plan (data amounts are very small)
  • GPS reception

Future directions

The principle of RowingCAS is applicable in other contexts like personell tracking and machine avoidance in the Mining, Earth Moving, Shipping etc. industries. If you're interested in using consumer hardware for these applications, please don't hesitate to be in touch.