from Huki website - Jude Turczynski

This may require two people if the first set of tests don't reveal the source of the leak. The most common locations for leaks are the thru-hull rudder tube near the tail of the canoe, the footwell drain holes at the bottom of each well, the iako receiver holes, the sliding seat rod receiver holes, the lock hole in the footwell divider, the rivets holding down the hinges and the cable housing exits through the deck at the cockpit and at the rudder yoke, the ama iako mounts and button holes. There are other locations that will be dealt with later. DO NOT use a vacuum or other pumps to create a vacuum in the hull. This will crush the hull. DO NOT use compressed air or other pumps to create pressure inside the hull. This will explode the hull. The hull can only handle the amount of vacuum or pressure created by human lungs

• Remove the rudder blade and don't forget to memorize the order in which the washers come off. Thoroughly wash the thru-hull tube with fresh water. Seal your mouth over deck end of the thru-tube and seal your thumb or palm over the bottom end of the tube on the bottom of the hull. Now, try to blow air through the tube. If you can blow air through without it escaping from under your thumb, then there's a leak inside the tube or at one of it's ends (top or bottom). If you don't know whether or not there is air leaking, it could still be a very tiny leak, so now try sucking air through the tube. You can tell if there is even the tiniest leak by drawing air out of the tube. If you don't detect a leak, it's time to go on to the next probable location.
• Instructions for repairing

• Thoroughly wash the footwells, venturies and bottom of the hull with fresh water. Turn the canoe upside down and seal your mouth over the opening of the venturi. If you are able to seal your mouth over the entire venturi, then do so to make your testing more accurate. With your hand reaching into the corresponding footwell, place your thumb over the corresponding drain hole to seal it off completely. Now, try blowing air through the venturi. If you can blow air through without it escaping from under your thumb, then there's a leak inside the drain between the hull and the footwell. If you don't know whether or not there is air leaking, it could still be a very tiny leak, so now try sucking air through the venturi. You can tell if there is even the tiniest leak by drawing air out. If you don't detect a leak, it's time to go on to the next probable location.
• Instructions for repairing

• Thoroughly wash the iako receivers and surface of the canoe with fresh water. Turn the canoe right side up and then place your palm over the large iako opening to seal it off and then seal your mouth over the button hole. Now, try blowing air through the button hole. If you can blow air through without it escaping from under your palm, then there's a leak to the main canoe hull inside the receiver between the button hole and the receiver opening. If you don't know whether or not there is air leaking, it could still be a very tiny leak, so now try sucking air through the button hole. You can tell if there is even the tiniest leak by drawing air out. If you don't detect a leak, it's time to go on to the next probable location. If you're not sure that you were able to seal your palm or your mouth correctly. Place some masking tape or packaging tape over the button hole, then turn the canoe so that the iako receiver holes open upward towards the sky. Fill the iako receiver hole with water all the way to the top of the hole so that water fills as evenly as possible around the rim of the receiver hole. Have a second person blow air into the snorkel of the rubber drain plug with their mouth (do not use compressed air for this as you will explode the canoe) to raise the internal air pressure. Using a flash light to see deep into the iako receiver hole, watch for bubbles to appear and try to determine exactly where they're starting from.

• Set the canoe level and right side up. Slide the seat all the way back in it's track and pour water into the slide track trough to fill it to the rim. Have a second person blow air into the snorkel of the rubber drain plug with their mouth (do not use compressed air for this as you will explode the canoe) to raise the internal air pressure. Watch for bubbles to appear at either end of the slide track where the rod enters through the surface of the boat.
• Instructions for removing slide track seat