Jan 29, 2018 - 1:00 AM
You need to go to www.bls.ch and download the pdf timetable for boats on Lake Thun and Lake Brienz. Be sure to read the summer schedule.
You are trying to fit a lot into one day so will need to check how the boats will fit into your plans. I have used the timetable to create 2 or 3 possible itineraries for you but obviously you can create your own.
1. Aim to catch first boat from Thun at 9.40. Leave Wengen at 7.33, arrive Thun at 9.03. The 8.03 from Wengen gets you to Thun at 9.32 - a bit tight to get from train to boat I'm afraid. (If you did try that and missed boat you could catch no 21 bus instead.) Boat reaches Oberhofen at 10.03. Castle doesn't open till 11 AM. so explore the gardens first.It then depends how engrossed you get in the castle! Boats leave Oberhofen at 12.03 and 13.03, arriving at Beatushohlen Sundlauenen at 13.17 and 14.17. If you take the earlier one you could stop for an hour's stroll in Spiez (no time for castle visit though) and pick up the second one (1st arrives Spiez at 12.28 and 2nd leaves at 13.28.) After the caves there are boats to Interlaken at 15.17 and 17.17 (arrive Interlaken 15.49 and 17.49.
2. Follow your original plan but there should be train to Thun from Spiez half an hour earlier which would make it easier to connect with 12.40 boat. (arrives Oberhofen at 13.03 - not much time to spend in Oberhofen though and there isn't a 15.03 boat. so you would need to leave Oberhofen on the 14.03 boat, arrive Beatushohlen at 15.17 for visit to caves. You could catch no 21 bus from Oberhofen to caves instead. There is then the 17.17 boat back to Interlaken but if caves take too long there are plenty of buses (no 21) back to Interlaken.
3. Compromise - get to Spiez earlier or spend less time there and aim to get 11.40 boat to Oberhofen. Arrive 12.03, leave for caves at 14.03.
4. Trying to do trip in opposite direction is tricky because first boat from Interlaken doesn't leave till 11.10 a.m. , arriving at Beatushohlen at 11.43 for caves. Boats from there to Spiez are at 12.43 and 14.43 - not best timings so I would get a bus from Interlaken to the caves so you can catch 12.43 boat. That will arrive in Spiez at 13.32. You can get off there if you wish for 2 hours or stay on board to Oberhofen - arrive 13.57 giving you time to visit castle and gardens. Next boat leaving Spiez is at 15.34 so not arriving in Oberhofen till 15.57 which may be too late for last entry to castle though you could explore gardens. So you would have to choose between Spiez and Oberhofen. There is a boat going to Thun from Spiez at 16.34 as well. Getting back from Thun is easy enough - choose between train via Spiez or bus 21 all along north shore - a nice ride.
Food - take a picnic! Or eat on a boat - nice snacks. If time in Oberhofen can recommend café on main road - tea room Berger - excellent food though service is sometimes a bit slow because they cook as you order - lovely omelettes!
Word of warning - Monday not a good day for castles and museums - Oberhofen not open on Mondays!
Ps Post number 500!!