Shamelessly stolen from another forum. But so funny and true, I had to share it.
Class I, Easy. Fast moving water with riffles and small waves.
Swimming is pleasant, shore easily reached. A nice break from
paddling. Almost all gear and equipment is recovered. Boat is just
slightly scratched.
Class II, Novice. Straightforward rapids with wide, clear channels
which are evident without scouting. Swimming to eddies requires
moderate effort. Climbing out of river may involve slippery rocks and
shrub-induced lacerations. Paddle travels great distance downstream
requiring lengthy walk. Something unimportant is missing. Boat hits
submerged rock leaving visible dent on frame or new gash in plastic.
Class III, Intermediate. Rapids with moderate, irregular waves which
may be difficult to avoid. Water is swallowed. Legs are ground
repeatedly against sharp, pointy rocks. Several eddies are missed
while swimming. Difficult decision to stay with boat results in
moment of terror when swimmer realizes they are downstream of boat.
Paddle is recirculated in small hole way upstream. All personal
possessions are removed from boat and floated in different
directions. Paddling partners run along river bank shouting helpful
instructions. Boat is munched against large boulder hard enough to
leave series of deep gouges. Sunglasses fall off.
Class IV, Advanced. Water is generally lots colder than Class III.
Intense, powerful but predictable rapids requiring precise swimming
in turbulent water. Swimming may require `must' moves above dangerous
hazards. Must moves are downgraded to `strongly recommended' after
they are missed. Sensation of disbelief experienced while about to
swim large drops. Frantic swimming towards shore is alternated with
frantic swimming away from shore to avoid strainers. Rocks are clung
to with death grip. Paddle is completely forgotten. One shoe is
removed. Hydraulic pressure permanently removes waterproof box with
all the really important stuff. Paddle partners running along stream
look genuinely concerned while lofting throw ropes 20 feet behind
swimmer. Paddle partners stare slack-jawed and point in amazement at
boat which is finally pinned by major feature. Climbing up river bank
involves inverted tree. One of those spring loaded pins that attaches
watch to wristband is missing. Contact lenses are moved to rear of
eyeballs.
Class V, Expert. The water in this rapid is usually under 42 degrees
F. Most gear is destroyed on rocks within minutes if not seconds. If
the boat survives, it is need of about three days of repair. There is
no swimming, only frantic movements to keep from becoming one with
the rocks and to get a breath from time to time. Terror and panic set
in as you realize your paddle partners don't have a chance in heck of
reaching you. You come to a true understanding of the terms
maytagging and pinballing. That hole that looked like nothing when
scouted, has a hydraulic that holds you under the water until your
lungs are close to bursting. You come out only to realize you still
have 75% of the rapid left to swim. Swim to the eddy? What #%^&*#*
eddy!? This rapid usually lasts a mile or more. Hydraulic pressure
within the first few seconds removes everything that can come off
your body. This includes gloves, shoes, neoprene socks, sunglasses,
hats, and clothing. The rocks take care of your fingers, toes, and
ears. That $900.00 dry suit, well it might hold up to the rocks. Your
paddle is trash. If there is a strainer, well, just hope it is old
and rotten so it breaks. Paddle partners on shore are frantically
trying to run and keep up with you. Their horror is reflected in
their faces as they stare at how you are being tossed around! They
are hoping to remember how to do CPR. They also really hope the
cooler with the beer is still intact. They are going to need a cold
one by the time you get out! Climbing out of this happens after the
rapid is over. You will probably need the help of a backboard,
cervical collar and Z-rig. Even though you have broken bones,
lacerations, puncture wounds, missing digits & ears, and a
concussion, you won't feel much pain because you will have severe
hypothermia. Enjoy your stay in the hospital: with the time you take
recovering, you won't get another vacation for 3 years.
Class VI, World Class. Not recommended for swimming.