What a water taxi is here
It is a boat used the way you would use a car: to get from one town to another, at an hour that suits you, with your luggage or your dinner reservation in mind. That is a real and distinct category on this lake, and it is priced differently from a tour — by the leg, or by the boat, rather than by the sightseeing.
The companies doing it are based around the southern basin: Peschiera del Garda from Piazza Maestro Giulio Battistoni, Sirmione from Piazza Carducci, Salò from Porto Sirena, and a lake-wide operation out of Porto Barbarano; one of the Sirmione tour companies also sells a private taxi-boat run.
The prices that are actually published
Per person, on set south-basin routes: 10 EUR around Peschiera, 20 EUR to Sirmione or Lazise, and 35 EUR for the long run out to Isola del Garda. Privately, with the boat to yourselves, a taxi run starts from 100 EUR.
That crossover is the whole decision. Two people going to Sirmione are better off per-person; six people going to dinner are better off taking the boat. Short taxi-style runs and tours of 30 minutes to 3 hours sit in the same bracket, and on the Brescia shore the published range runs 30 minutes to 4 hours plus restaurant runs across the gulf.
Taxi, ferry or your own boat
Ferry is cheapest and slowest, and it has a timetable: the main season runs 16 May to 4 October, the Desenzano-Sirmione-Riva line from March, and the Maderno-Torri car ferry all year. Desenzano to Sirmione takes about 20 to 30 minutes on the scheduled crossing.
Water taxi costs more and leaves when you want. It is the right answer for a late dinner, an early train, a group with luggage, or a hotel with its own steps down to the water.
A charter is the answer when the point is the boat rather than the destination — Sirmione’s published tour prices run from 100 EUR for a 25-minute peninsula circuit to 1,300 EUR for a full 8-hour day.
For the island specifically, note that Isola del Garda is served from eight ports with crossings of 10 to 60 minutes, that the visit is priced including the boat at 39 to 49 EUR for adults, and that it must be booked online at least the day before, never by phone.
Rules, safety and the weather
Taxi boats are commercial boats with professional captains, carrying life jackets as standard and working to the lake’s navigation rules — 300 m off shore, 20 knots by day, 5 knots at night and 3 knots in port. Note that private motorboat navigation is prohibited in the Trentino waters at the north tip, so plans up there are built around commercial boats.
The season runs April to October. The wind turns twice a day and summer afternoons can bring a thunderstorm; if a crossing cannot be made safely the skipper says so, and the lake norm is free cancellation 24 to 48 hours ahead with a refund or a reschedule.
If it is the boat you want rather than the crossing, start with the boat tour from Sirmione, the boat tour from Salò or Sirmione to Isola del Garda. The whole lake sits on the Lake Garda page, and boats in every other destination on boat charters. Request availability with your date, the two points you want to travel between and the time you need to be there.