Icy, glacier-sourced streams feed the Po Chhu or “Father River,” which energetically tumbles its way southwest towards Punakha and its confluence with the Mo Chhu (“Mother River”). Rafting trips along the upper Pho Chhu start with a series of Class IV rapids immediately below the tiny village of Wangthangkha. Further downstream, experienced rafters and kayakers will enjoy the big, bouncy Class III rapids as the fast-flowing river eases and slows. The first few sections of rapids should be scouted from the bank (scouting time included in the estimate below), while the lower rapids are generally boat scoutable. The first possible take-out point is 7km (4.3 miles) downstream from Wangthangkha at Samdingkha, but — if you're having too much fun to stop — it's only another 7km downstream to Punakha Dzong itself.