It is supposed to rain, but I crawl out of my tent under a bright sky. It has been bright since 4.30 am, daybreak in Arunachal Pradesh—for the love of god, somebody give the Northeast a time zone of its own.

I brush my teeth in an endlessly flowing tap near the toilet tents, where a length of split bamboo channels a little stream. A couple of other rafters are up, admiring the mist-draped Siang river below. I admire it a bit warily; this is my first rafting trip since 2006, when I almost kicked the bucket in the Zanskar river in Ladakh. The Siang’s silver twists seemed quite friendly on the five-hour car ride up from Pasighat to this put-in point at Geku Camp, but rivers are wild and must be respected—all our night halts are above the spate line.

Our group has non-swimmers, a couple of very experienced river runners, including the legendary Andy Leemann, and a couple of people like me, with a little experience. After breakfast and a safety briefing, we set off on our three-day rafting expedition.

This is a moderate stretch, with rapids no more than Class 3+. Rain has quietened the biggest ones a little, but they’re huge enough for me to love rafting all over again. There is nothing quite like attacking thrashing hills of freezing water with a paddle, bracing as the raft bucks, shrieking as the knife-like spray hits, and feeling your heart hammer in anticipation, exertion, and then exhilaration.

The non-paddlers have a great joyride. In calm stretches, some of us swim alongside the rafts and try