In the event the Apollo 11 Command Module Columbia splashed down beyond the recovery force helicopter range, a recovery aircraft was prepared to drop a sea anchor device, consisting of two sea anchors at the ends of a 600-foot floating line. The astronaut crew was to deploy a snagging line hook through the side hatch pressure equalization valve port after removing the valve. The hookwould then drift over the sea anchor line, snagging the line and retarding the drift speed of the command module while it awaited rescue and recovery.
The Apollo 11 snag line was stowed in this bag in a locker beneath the astronaut couches. The bag was transferred to the Smithsonian in 1970.