That top thwart bag would be the first thing to be ripped away and lost in a flip in whitewater. I have the other thwart bag that you showed by GG and mine actually has a hip strap that tucks away so you wear it as a fanny pack on portages. Also good to mention that all of those bags will hang down and fill up with water in a flip so don't store anything in them that should not get wet in them even the waterproof zipper ones sometimes.
We have the Granite Gear under seat bags and keep things we need at hand, and emergency items if we did a day trip from base camp and were not able to return due to weather. If you don’t overfill them, they are awesome and stuff stays dry. We put things that can’t get wet in ziplocks and small dry containers.
That top thwart bag would be the first thing to be ripped away and lost in a flip in whitewater. I have the other thwart bag that you showed by GG and mine actually has a hip strap that tucks away so you wear it as a fanny pack on portages. Also good to mention that all of those bags will hang down and fill up with water in a flip so don't store anything in them that should not get wet in them even the waterproof zipper ones sometimes.
We have the Granite Gear under seat bags and keep things we need at hand, and emergency items if we did a day trip from base camp and were not able to return due to weather. If you don’t overfill them, they are awesome and stuff stays dry. We put things that can’t get wet in ziplocks and small dry containers.