Finding a leak
Also: finding the hole, leak detection
Before you patch, you have to find the leak. Soapy water shows the spot most reliably with bubbles.
First check whether it really is a leak: in cold water every boat loses some pressure (temperature effect). Then inflate the boat fully, listen away from the river noise and feel with your hand. Alpacka recommends pouring water on the floor seam and spraying soapy water section by section; it has to be very soapy. Watch the stress points: grab loops, seat area, footwell, valves. Alternatively, submerge the lightly inflated boat.
Tip: mark the spot right away with a waterproof pen as soon as the boat is dry. After deflating, tiny holes are otherwise hard to find again.
Sources and further reading
Research as of 13 Nov 2026. We have marked manufacturer information as such.