Booking choice: The boat day pass for both lakes, from $50 per person. Check dates Tour details
Lake Thun is the bigger of Interlaken's two lakes and the busier one, in a good way: more piers, more towns, more to do ashore. BLS runs the scheduled boats from Interlaken West to Thun all year, zig-zagging between the two shores past Spiez, Oberhofen and the cliffs below Beatenberg.
It is a long ride end to end, about two hours, and that is the main thing to plan around. Most people sail one way, stop somewhere on the way, and come back by train.
The quick answer
Interlaken West to Thun takes about 2 hours on the scheduled boat, with stops including Spiez, Oberhofen and the St. Beatus Caves. A full-price BLS day ticket for both lakes costs CHF 83 in 2nd class (2026), and the Swiss Travel Pass covers it. Sail one way and take the train back.
How long is the boat from Interlaken to Thun?
About 2 hours end to end on the scheduled BLS boat, from Interlaken West to the pier at Thun station.
The boat crosses back and forth, so you see both shores. The north shore below Beatenberg has the St. Beatus Caves, Merligen, Gunten, Oberhofen and Hilterfingen; the south shore has Leissigen, Faulensee and Spiez. Not every course calls at every pier.
| Stop | Shore | Why get off |
|---|---|---|
| Neuhaus (Unterseen) | North | First stop out of Interlaken |
| Beatushöhlen-Sundlauenen | North | St. Beatus Caves, about 20 minutes' walk up |
| Beatenbucht | North | Turnaround point of the BLS short cruise |
| Spiez | South | Castle on a promontory, vineyards, trains |
| Oberhofen | North | Castle museum and lakeside park |
| Hilterfingen, Hünibach | North | Hünegg Castle |
| Thun | West end | Old town, Thun Castle, trains back |
Can I take a boat from Thun to Interlaken?
Yes. The same scheduled boat runs the other way, from the pier in front of Thun station to Interlaken West, in about 2 hours.
Starting in Thun is handy if you come from Bern or Zurich: the train drops you next to the pier. BLS says the Thun and Interlaken West piers are both next to the train stations, so a boat one way and the train the other is easy. By rail, Thun to Interlaken is just over half an hour.
★★★★★Very nice day cruising Lake Thun. The boat was very clean and comfortable with nice amenities. Everything was on time and the scenery was stunning. I highly recommend.
Start at Thun or Interlaken West: the day pass covers every scheduled boat on the lake.
Check dates for the boat day pass for both lakesWhich castles can you see on a Lake Thun cruise?
BLS lists five: Thun, Schadau, Hünegg, Oberhofen and Spiez. Oberhofen and Spiez have their own boat stops; Thun Castle is a short walk up from the Thun pier.
Oberhofen Castle is a living museum with a lakeside park, open from mid-May to the end of October; adults pay CHF 12, children 6 to 16 CHF 5 (MySwitzerland). Spiez Castle sits on a peninsula with about 1,300 years of history and a tower with a 360° view, open Tuesday to Saturday from 10 to 17 (to 18 in July and August), at the same prices. Thun Castle costs CHF 10 for adults and is free with the Swiss Travel Pass, per Schloss Thun; it opens daily from April to October.
Spiez needs one warning: the pier is about a 15-minute walk down from the station, per BLS, and the walk back is uphill. Leave time for it if you have a train to catch.
All three big castles in one morning without timetables: a minibus along Lake Thun to Oberhofen, Thun and Spiez, with a guide and entry to one castle. There is no boat on this one.
Explore the Lake Thun castles tour Tour detailsHow do you get to the St. Beatus Caves by boat?
Get off at Beatushöhlen-Sundlauenen, on the north shore, and walk about 20 minutes up the trail. BLS sells a combined boat and cave ticket from Interlaken West, Thun and Spiez.
About one kilometre of the cave system is open to visitors, on a circular path with 297 steps, per MySwitzerland. Interlaken Tourism puts the temperature inside at 8 to 10 °C, so bring a layer even in July. A waterfall runs out of the cave, and the path crosses it on bridges on the way to the entrance. The legend says Saint Beatus drove a dragon out of the caves.
The BLS combined ticket from Interlaken West costs CHF 30.40 for adults in 2nd class (2026) and covers the boat one way, the bus the other way, the cave entry and the museum. From Thun and Interlaken it is sold all year; in winter the path is not cleared of snow.
When does the Blümlisalp paddle steamer sail?
In the summer months on marked courses, plus evening runs: the after-work cruise sails Tuesday to Saturday until 29 August (not 1 August) and from 1 to 19 September 2026.
The Blümlisalp is a double-deck saloon steamer built in 1906. After about two decades laid up, it was restored from 1989 to 1992 with money from a nationwide fundraising campaign and returned in May 1992, per BLS. MySwitzerland adds that it also sails between Christmas and New Year.
It is a scheduled boat, so a normal ticket or a travel pass gets you on. Passes do not cover culinary and event cruises, so if a themed dinner trip catches your eye, check its fare separately. The 2026 BLS timetable marks which departures the steamer runs.
How much does a Lake Thun cruise cost?
A full-price BLS day ticket for Lakes Thun and Brienz costs CHF 83 in 2nd class and CHF 125 in 1st (2026). With a Swiss Travel Pass, the GA or the Berner Oberland Pass, the scheduled boats are included.
The scheduled BLS boats on both lakes are fully covered by the Swiss Travel Pass (the Flex version with the day entered), the GA travelcard, the Berner Oberland Pass and Eurail or Interrail with the date entered. The Half Fare card gives 50% off. Children 6 to 15 pay half or take the CHF 15 kids day ticket; under-6s ride free. Dogs pay CHF 15. The both-lakes day ticket also covers the train between Interlaken West and Ost and the Interlaken buses, per BLS. BLS sells discounted day passes online in limited numbers; April is half price.
Without a pass, the boat day pass (from $50, 4.2 from 223 reviews) is the ticket: Lake Thun all season, Lake Brienz from early April to mid-October.
| Ticket (2026) | Price |
|---|---|
| BLS day ticket, both lakes, 2nd class | CHF 83 |
| BLS day ticket, both lakes, 1st class | CHF 125 |
| With Half Fare card, 2nd / 1st | CHF 41.50 / CHF 62.50 |
| Kids day ticket, 2nd / 1st | CHF 15 / CHF 24 |
| Swiss Travel Pass, GA, Berner Oberland Pass | Included |
Sail Lake Thun from Interlaken West or Thun, hop off at Spiez or Oberhofen, and use the same pass on Lake Brienz in season.
Explore the boat day pass for both lakes Tour detailsIs a Lake Thun cruise worth it?
Yes, if you plan a stop. The full two hours straight through is long for some people; one leg by boat with an hour at Spiez or Oberhofen is the sweet spot.
The lake changes as you go: cliffs and the cave stop near Interlaken, vineyards and castles in the middle, villas and parks near Thun. If you only have a couple of hours, BLS runs a short round trip from Interlaken West to Beatenbucht and back in about 1 h 40. One reviewer put the time argument in one line:
★★★★★back and forth I think is unnecessary. going by boat and returning by train saves time.
Lake Thun is also the lake for the cold months. It runs all year, while Lake Brienz stops after early December. Expect fewer boats from mid-November to March.
Which is better, Thun or Interlaken?
As a base, Interlaken: it sits between both lakes and has the Jungfrau trains. As a place to visit, Thun is the better town, with a real old town, a castle and the Aare.
Thun is a town in its own right at the lake's west end. The old town runs along the Aare, the Obere Hauptgasse has its raised pavements, and the castle above holds about 800 years of history, per MySwitzerland. Schadau Park, laid out as an English garden, is by the lake. Ending a boat day here and taking the train back is a good afternoon.
Interlaken wins on logistics. Interlaken West serves Lake Thun, Interlaken Ost serves Lake Brienz and the mountain trains, and the Jungfraujoch day starts in town. Planning a few days of lakes and mountains? The Berner Oberland Pass covers both lakes' scheduled boats along with the trains.
Boats on both lakes, trains and over 25 mountain railways on one pass, for 3 to 10 days.
Check dates for the Berner Oberland PassFrequently asked questions
Is the Lake Thun cruise free with a Swiss Travel Pass?
Yes. The scheduled BLS boats on Lake Thun, including the Blümlisalp steamer, are covered by the Swiss Travel Pass, the GA and the Berner Oberland Pass. Culinary and event cruises are not.
Where does the Lake Thun boat leave from in Interlaken?
From Interlaken West, next to the station. Lake Brienz boats leave from Interlaken Ost; there is no boat between the two lakes.
Does the Lake Thun boat run in winter?
Yes. Lake Thun has boats all year, with a reduced winter timetable from 15 November to 12 December 2026 and again in the early months of the year.
Which boat stop is closest to the St. Beatus Caves?
Beatushöhlen-Sundlauenen. From the pier a trail of about 20 minutes leads up to the cave entrance.
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Choose your trip
Free cancellation up to 24 hours before on every option. Prices are from-prices in USD and move with the season.
Boat Day Pass: Lake Thun & Lake Brienz
- Day pass on the Lake Thun boats
- Lake Brienz boats too: early April to mid-October on this pass
- Hop on and off at any pier
Lake Thun: 3 Castles Tour with Entry
Oberhofen, Thun and Spiez with a guide and one entry
Berner Oberland Pass, 3 to 10 Days
Boats, trains and over 25 mountain railways on one pass
