Carby overflow hose....HELP PLS!!

[Fish Baseball]

ok, so here goes. Went out in the steel cage today with the family, brilliant sunshine when i left. Left the bike on the path out the front of the house, thinking that this wonderful day couldn't get much better. Hell, even had the sunroof of the 4wd open. Fast forward about two hours, and Melbourne cops a massive storm. Flooded roads, destroyed gardens, thankful I'm in the 4wd and not a car. Get back home to find the GZ still sitting upright, no damage from the hail (bout the same size hailstones as the top bit of your thumb) but this black tube just hanging out from the bottom of the carb. Start her up fine, sounds as good as she did yesterday when i took her for a run, thou the black tube is just hanging there. Pull out the service manual (thanks guys!) and this is the only reference i could find to it.

is the image from the manual.

highlighted in red is the tube i'm talking about.
am i right on this one or is it something else? Help?