I just did this last week and it is very doable, however the river was low given the time of year and I took a couple of small holes to the bottom of the packraft.
It was my first time in Indonesia, so I suspect I was slightly ripped off but these are the broad details I gathered:
- From Ubud, I paid 100 000 IDR for a scooter driver to take me to Melinggeh Kelod, where many of the whitewater rafting companies are based and have their put-ins into the Ayung River;
- On the way to Melinggeh Kelod, the scooter driver stopped at the office of Ayung Dewata, the only rafting company I could find that would allow me to rent only a lifejacket and helmet versus an entire rafting trip. Day hire of the kit cost me 200 000 IDR but I sensed this could have been bartered if you’ve the patience;
- Once at Melinggeh Kelod, I asked the scooter driver to ask for Sobek rafting office (one of the biggest in the village);
- From the Sobek office, instead of going into it I headed 200m or so north up the road where a concrete lay-by leads up a short staircase west into some rice paddies;
- Continuing west 100m, once up the staircase, you start to see worn footpaths heading down to the river and a long footpath descent begins;
- The put-in is marked by a concrete bay with a roof, where loads of whitewater rafting tours leave each day and there are guides inflating boats/overwatching;
- From the put-in there is about a 9.5KM stretch of river running south until just west of Ubud with Class II-III rapids. Periodically, just after rapids there are small stalls with vendors selling snacks/drinks at the riverside;
- Ask the river guides you pass on the river what’s up ahead as there is a fairly substantial fall/drop once you past about 9.5KM. I didn’t go to it nor beyond that point so can’t comment further;
- From the take-out point, you walk up the hill on the east side of the river and are about a 10 minute scooter ride (40 000 IDR) into Ubud.
Overall, it was my first time on a river in a packraft and absolutely terrific. I snapped my paddle 100m into the course, running the river with just half of it and capsizing once but am certainly hooked. Everyone on the river was very curious about the packraft and tremendously helpful in giving advice on the rapids ahead.