>>2769354you need to layer
my setup is:
- put expensive electronic gizmo into a hydration bladder
- add paper towels / newspaper bits hoping to soak any intruding moisture and condensate
- inflate the hydration bladder with air to achieve positive pressure
- put the hydration bladder into a drybag
- put the drybag into a thick PVC caving bag
a more typical solution is using a (dry) drum instead of a bag type container:
https://www.elevatedclimbing.com/products/darren-drum