Saildrone Voyager: Surveillance drones flying the Danish flag. The implications

According to the US company Saildrone, vessels from its fleet are now operating under a national flag for the first time. To this end, Saildrone and the Danish Maritime Authority have drawn up a legal framework for unmanned surface vessels. The Voyager vessels, which are around ten metres long, were already tested for the Danish Navy last year. BOOTE reported on the test deployment in the Baltic Sea. The Dannebrog visible on the sails was not to be equated with an official flag registration. It is precisely this formal classification that is now new.

What the Danish flag means

A registered ship is assigned to a flag state. That state must, in accordance with the Principles of the International Maritime Organisation exercise supervision over ships flying its flag, particularly in relation to administrative and technical matters as well as safety. However, it is for the competent authority to determine which rules are to be applied in practice to an unmanned vessel.

Nor does the flag alone permit just any use. The Danish guidelines for marine drones sets out the requirements for separate authorisations and risk assessments for commercial operations in Danish waters. Among other things, the assessment will examine how the drone affects the safety of other maritime traffic.

The flag does not determine who is liable for costs in the event of a collision

If a collision occurs, the flag is not the answer to the question of compensation. According to the Danish maritime law Where one party is solely at fault, that party is generally liable for the damage. If both parties are at fault, the damage is apportioned according to their respective shares of responsibility. Whether an insurance company covers the claims is a separate matter.

Specific statutory insurance obligations depend on the gross tonnage. From a gross tonnage of 20 upwards, insurance or other financial security is required to cover certain claims arising from wreck removal. From 300 upwards, additional requirements apply for the cover of claims under maritime law. These thresholds do not indicate whether or how an individual vessel is insured beyond these limits.

Gross tonnage is neither the weight nor simply the length of a ship. For vessels such as the Voyager, with a measured length of less than 15 metres, the Danish regulations for smaller vessels a calculation based on a defined hull volume. A gross tonnage of 20 corresponds to approximately 84 cubic metres of this measured volume. Saildrone states that for the The Voyager is ten metres long and has a draught of two metres, but there is no official gross tonnage figure and the hull dimensions are insufficient for a calculation. Given the vehicle’s slender, flat shape, a gross tonnage of more than 20 seems unlikely.

What motorboat drivers should bear in mind

Whether the Voyager, after the Rules for the prevention of collisions Whether it is classed as a sailing or motorised vessel depends on the type of propulsion used. If it is sailing under sail alone, a motorboat may be obliged to give way to it. If it is using its electric motor, it depends on the specific encounter. Our guide explains the classification BOOTE Guide to the KVR rankings.

For motorboat operators, the practical implication is clear: anyone who spots the drone should, in their own interests, pass it well in advance and at a generous distance, rather than relying on the Voyager’s theoretical obligation to give way. It is impossible to judge with certainty from one’s own helm whether its engine is running and how quickly it will react. However, if a specific avoidance situation has already arisen, a boat operator must not change course unexpectedly: they must initially remain predictable; if the drone fails to react, they must, if necessary, take action themselves to prevent a collision. Our BOOTE article explains why this is not a contradiction “Why right of way alone does not prevent collisions”.

What information about unmanned vessels would be helpful to you if you came across one at sea? Join the discussion.