Wednesday, July 25, 2007

Missouri 340: Between CP4 and CP6

The plan for this afternoon (Wednesday), according to SB, is to paddle downriver toward CP5(Coopers Landing.) It's about 56 miles from CP4 to CP5. If all goes well, SandyBottom, SOS, and "the peloton" might make it to CP6(Jeff City) before setting up camp. CP5 to CP6 is about 26 miles.

Update: Son-0f-Sandy (SOS) called in at about 6:30 pm (Central time) to report that he and SandyBottom were paddling away from a rest stop at the boat ramp at Frankin Island (near mile marker 195) where they had met up with Stan and Dana. All were reported doing well. SOS said their plan was "to paddle a long long time to a camp site a long long way down the river". Well yes, that is the essence of the MR340 and why worry with the small details. SOS also reported that he photographed a water snake today, and that the concensus was that the river was flowing at about 3 mph. We want the river to flow fast.

Is it really the "Missouri 170" ?

If you normally paddle 3 miles in 1 hour on a calm flat lake, just think what happens when you paddle downstream on a river that is moving at 3 mph. The pool of water you are paddling in is traveling at 3 mph and you are paddling across that pool at 3 mph. In 1 hour of paddling you will travel about 6 miles downriver. The point is, a 6-mile non-stop paddle down the river will "feel like" a 3-mile non-stop paddle on lake water. So when the river is moving at the same speed you normally paddle, the distance "feels like half". When the river contributes 3 mph and you contribute 3 mph, then a 100-mile paddle downriver will "feel like" a 50-mile lake paddle.

But that assumes there are no headwinds. Wind moving upstream can easily cancel the river's contribution to forward progress. In 2006 the last section of the race course featured a strong headwind. (It also assumes that air resistance effects are negligible as the paddler moves through two fluids: water and air.)

There doesn't seem to be easily obtainable information about how fast the Missouri is flowing. I've heard that 3 mph is a good guess for purposes of planning a trip, that 5 mph is plausible, and that the main deep channel in the center can be 1 mph faster than near shore. Of course there are also swirling eddies behind rocks/barriers in the river, with still pools and even counter-flows upstream --very useful if like Lewis and Clark you're trying to go upstream.

The MR340 adventure racers are out there right now trying to stay in the fastest parts of the downriver flow.

The speed of the river can be a great equalizer

On a calm lake a 4-mph paddler is 100% faster than a 2-mph paddler. But on a 3-mph river, the two travel at 7 mph and 5 mph --and now the faster paddler is only 40% faster. Fast paddlers should favor a slow river while slower paddlers should hope for a maximum river speed.

Here is a look at the current wind report and radar for Missouri:

Blue is calm, green is windy.

Nothing on the radar now
(4:30 pm Central Time).

1 comment:

Dee said...

Geez Paul, you really are a paddling geek! Nobody will forget that you work with numbers. Joking aside, this is all really interesting to think about. It's definitely not a simple thing to predict how much current will help or hurt with all the other factors.

Glad both Dawn and Alan are doing so well!