GAS! Quick, boys! - An ecstasy of fumbling/ Fitting the clumsy helmets just in time." Starting the stanza by impersonating an officer warning his men, then using the description of ecstasy of fumbling for their masks all adds to the sensory detail regarding the chaos of the scene. The stanza continues with the speaker describing one man not fortunate enough to get his mask on as he begins to feel the effects of the gas. From the speaker's perspective the man is "drowning" in a "green sea" which is a graphically realistic way of describing death by gas. As a "sea of green" the gas was likely chlorine which was lethal due to its ability to cause victims' lungs to flood with fluid. The man's death was akin to drowning in the actual sea.
The speaker continues the description by admitting that the image of that poor soldier drowning in his own lungs is scarred into memory: "In all my dreams before my helpless sight/ He plunges at me, guttering, choking, drowning." Not only does the speaker convey visual sense to the reader, but now includes sickening sounds as the auditory description of the soldier choking is given. As the image is scarred into the memory of the speaker, and the author gives such a detailed description, it is possible this very event could be the recollection of something etched into Owen's own memory as a true