Who you deal with
The Transport Authority's inland navigation division in Bratislava, with offices at Komárno, Žilina and Košice.
At twelve passengers
A national small-vessel licence. An Estonian skipper's licence is accepted directly, with no recognition procedure. One thing to plan for that nobody mentions until you are committed: the boat goes onto the Slovak Transport Registry, and it has to come off your own national register first, because a vessel cannot sit in two at once. We have done this ourselves at twelve passengers and it was straightforward.
At twenty passengers
Slovak law makes classification by a recognised classification society mandatory for vessels up to 20 m intended to carry more than twelve passengers. Of all thirty-one countries in this document, Slovakia is the only one where that is genuinely unavoidable.
Who may drive it
An Estonian ticket is accepted directly, which is unusual across Europe and worth knowing.
Hiring it out without a crew
Slovak law contains rental relief provisions.
Where the engine matters
We found no restriction on the Danube, which makes Slovakia one of the clean propulsion answers. Above twelve passengers on this country's inland waterways, petrol is not an admissible fuel at all, so the twenty-passenger inland configuration would need a different form of propulsion. This does not apply at sea, and it does not apply at twelve passengers.