|Quoting yeelep (Reply 1):|
That said , the slide on a 737 could possibly be used as a flotation device by cutting it away from the girt bar.
Evacuation slides (that are not side/rafts) can generally be easily detached to use as a flotation device without the need to cut the girt. For the 737 series it is simply a matter of lifting the girt flap and pulling the white separation handle. (Even though it is not a slide/raft, it still has this feature). The slide will remained attached via a mooring line that can be detached or cut.
You can see this illustrated in this safety card (it is not normally shown on most cards): http://cabinsafety.com/samples/airliners/73m.html
Many carriers will recommend to their crew to flip the flotation slide around since there is the center of the upside down slide is actually big enough to put passengers who need serious assistance (e.g. children) in it. The slide is actually pretty buoyant despite not being a slide/raft.
You can actually see a cabin crew training video here on the slide's (not slide/raft) ability to keep people afloat: http://www.youtube.com/watch?v=4Ym-d8O6I8w