Solo Sailor

Collision avoidance at sea

One of the biggest challenges as a solosailor is the avoidance of collisions with other vehicles. See also When can I sleep? und How do I keep a good "look out"? But even if you are travelling with a crew it happens again and again that one recognizes other boats (too) late. I think every skipper will confirm this. Nowadays there are already technical systems that are helpful in avoiding collisions at sea. I am thinking in particular of AIS and the on-board Radar. However, both have disadvantages: There is no obligation to equip a boat with AIS if it has a gross tonnage (GT) of less than 300, which means that recreational craft are only displayed on the AIS if the owner has voluntarily installed a transmitter. Also a Radar is not mandatory on smaller vehicles. In addition, both systems are relatively expensive and their installation on many recreational craft is out of the question. For this reason, the project "BCAS - Boat Collision Avoidance System" was launched, which should fulfil the following requirements:

The solution to the problem is to create an "artificial lookout", which imitates the helmsman's work when searching the surroundings for other vehicles, using computer technology. Modern object recognition software is used, which continuously scans images of the boat's surroundings for other vehicles. If a boat is detected, the program determines its position and issues a warning. The following picture shows the first test installation from BCAS on a 12m sailing yacht.

Two 200° wide-angle cameras CAM 1 and CAM 2 take pictures of the ship's surroundings at short intervals, process them and send them to the central computer in the cockpit. Here the object recognition software searches for targets and issues warnings with the calculated directions. The data exchange between the cameras and the central server takes place via an on-board WLAN in order to keep the effort for the cabling as low as possible. The two cameras only need a 12V power supply from the onboard power system. Due to the distributed processing of the data in the cameras and in the central computer, the demand on the computing power of the hardware used and thus also the price level can be kept relatively low. The system runs "stand alone" and is completely independent of other on-board systems. The first tests have been very positive, here are some examples:

Not only the two freighters on starboard and port side were recognized, also the small pilot boat exactly ahead was reliably picked out of the image data.

A traffic situation on the Kiel Canal. Here it is remarkable that even against the dominant background the freighters were well recognized as such from both the front and the stern.

In this situation there was the fear, that the background with its many chimneys and windmills could lead to confusion with the masts of the sailing boat in the foreground. Nevertheless, object detection had also worked reliably in this case.

Sometimes boats collide with navigation signs, such as in August 2020 the Yacht "Sharki" west of Cuxhaven. Here BCAS shows, that it also recognizes buoys as such.

The BCAS project is in an early phase and is far from being ready for the market. Nevertheless, the first successes are encouraging and show as a "proof of concept" that it is possible to implement the idea of building a collision warning device using object recognition. If you have any comments or would like to participate in BCAS, please contact me at mail(at)

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