Wiktionary
drybag
alt. A bag used to keep things dry when in a wet or damp environment n. A bag used to keep things dry when in a wet or damp environment
Usage examples of "drybag".
The narrow ribbon of beach, furred with mesquite and salt cedar and willowbrake, seemed to continue indefinitely, but until he reached the third side canyon below the Maltese Cross, Tommy would let the river do the walking for him, as well as transporting his bulky drybag.
Before returning the camera to its Ziploc bag and putting it in the drybag, he twisted the zoom lens down to its 50mm focal length and, lying on his back, got the Maltese Cross on the focusing screen.