Change in the wind
The water always gets a lot thicker coming back in when I had a tail wind going out, (even a small breeze.) Do the winds shift from spring to summer?
Absolutely wrong !
You can be cruising along at five MPH in five to six feet of water, and as soon as you come into two or three feet of water it will be like putting on the brakes.
It is much harder to paddle in shallow water.
Cheers,
JackL
recently
RedCrossRandy and I were cruising at 6.4 mph in deep water. We were ahead of JackL and all the other stock tandems and cruisers. We came to shallow wateer and our speed dropped to 3.6 mph.
All the light teams ( read all the other teams) were able to keep it up over 3.8…
Shallow water SUCKS!
18"
kayaks and canoes will send DOWN a bow wave that in water 18" or less will rebound back up causing the bow to climb UPHILL to get over the wave. 18" and the rebound can’t be felt.
this was told to me by a long time canoe racer a loooong time ago and I believe him.
steve
Even less in a kayak
The smaller the displacement of the water the less the effect.
waater
It has been suggested that; since the water in question is still with very litle movement, that what I am feeling is an explosive growth of micro-organisms.and an alge that does not evolve into a [plant type of visable object] but stays suspended in the water.
I can say with certainty[sp] that you would not want to drink a glass of water straight from the bayou. It varys from brown to dark brown in colourand don’t look very apppitizing.
I thank you all for your replys.
Which brings up the question ?
You come up to a sand bar and completely run out of water.
The two of you jump out of your boat and start to run up and over the sand bar with it.
When you get to the rise of the sand bar, you notice that there is open water on the left where you can immediately put your boat in and continue paddling down river, or you can continue running forward for about another 25 yards to a point on the down river end of the sand bar.
Both choices put you at the same point in the river.
There is another tandem chasing you and you are trying to put as much distance between them and yourselves as you can so you you won’t be arriving at the next carry at the same time.
Which route would be the fastest ?
I wanted to run to the end. - Partner (“the bride”) who was at the bow of the boat chose the water on the immediate left
I need to know, so I can say; “I told you so”!
Cheers,
JackL
The correct term is viscosity
And I doubt that it is a measurable difference to have the effect you are talking about.
Water freezes at 32 deg & boils at 212 deg at sea level. The changes into those alternative states is quite dramatic a there is no noticeable increase or decrease in viscosity before hand.
have noticed it paddling or swimming
Sometimes the kayak moves through the water with ease and sometimes it seems to take more effort.
Before I began kayaking I noticed this viscosity variation while swimming.
There are times when the water in the same swimming pool seems easy to glide through and other times when I’ve felt like the water was actually thick and my speed slower than ever. Indoor and outdoor pools both so wind has not been a factor.
Density change would be tough to detect.
Density (specific gravity) will change with suspended solids such as salt, algae, silt, or the amount of malt in your beer. The “picnocline” is the line between lighter water and heaver water. You can see it when freshwater runoff floats on top of salt water until the two mix together. It would be hard to detect with a boat or a paddle though. The freshwater to saltwater differential is only about 2.5% (62lbs/cf : 64lbs/cf).
If any of your buddies brew their own beer or teach science, ask to borrow a hydrometer. Or, just use your paddle. With a loose grip on the shaft of your paddle, stick the blade in the water and see where it floats. Mark water line with tape or some other method. Later in the season, if the water is truly thicker, the paddle will float higher in the water.
As others have pointed out, hydrodynamic friction from shallow water getting shallower water might be more of the cause.
- Tom.
Hey Cher! Que sa dit vous?
Otis :
The term “Bayou”, is the key. Bayous usually contain a good deal of particulate matter. A lot of organic matter, silt, nutria guano, rotting leaves, etc. By late summer the build-up is high and it abates when the water starts cooling down and summer rains slack off in Autumn. In the deep south, that’s usually sometime in October. Also, bayous are deeper drainage channels that watershed swamps (pol. correct, “wetlands”) and after several days of rain more ditritus than usual enters the bayou. So, I suspect it’s not oxygen but has more to do with parts per thousand of particles in the water.
A plus tarde,
Pagayeur
Another term is "dead water"
and this link describes that devastating issue in the Chesapeake Bay:
http://www.cbf.org/site/PageServer?pagename=exp_sub_state_badwater_report
Another attribute exists for “dead water”, in that it has less density to effect propulsion of a boat:
http://en.wikipedia.org/wiki/Dead_water
It looks like we have less water, and some of that is dead water. We need to take care of what we have,
and work to make it better. While this pertains
to ocean shore waters, I have heard other reports
of “bad water” in inland waters that are stagnant. Happy paddling!
The heaviest water is that which
gets in my boat when I don’t want it to. I hate when that happens.
thicker, a tiny bit heavier, & Sucky
First of all water gets much thicker as it gets colder. I remember from my water treatment days that the viscousity of water more than doubles as it gets from normal temps to freezing. I have no idea if this is enough to affect boat performance, but it does affect filter and clarifier performance a good bit.
Secondly water gets a tiny bit heavier as it gets colder, but not enough that it would affect normal hydrodynamics.
And finally I know canoe races call shallow water suck water, for a good reason. in shallow water the bow wave of the boat reacts with the suface of the bottom and slows the boat much more than normal. If you get a chance you may be able to show the affect on your boat by testing the glide in shallow water versus deep water with your gps.
Stratification not viscosity
– Last Updated: Sep-30-07 6:01 PM EST –
It's true that the kinematic viscosity of water decreases by about 50% from near-freezing to room temperature. However, as pointed out by others, in itself this would make it easier to paddle in warm water. I think the answer is the 'dead water' phenomenon mentioned by mickjetblue. But it is the wave-induced dead water, not biologically dead water, a completely different and separate phenomenon.
The descriptions and (particularly) the video on the Wikipedia entry are quite revealing. If you paddle in a hot bayou, in calm conditions, there will be significant stratification of warm water over cool. The warm and cool bodies of water have different densities, and therefore an interface between them that is capable of supporting internal waves. Surface water waves are also internal, if you consider the air and water to be fluids of dissimilar density (they are). You can also see evidence of internal waves in the form of wave clouds between warm and cold air masses.
As shown in the short film, for conditions where the density interface is close to hull, the wave action can actually stop the boat in its tracks - shown in runs 4 & 6 on the film. Also, the boat can 'surf' the waves on the interface - this is what dolphins do in the bow wave of ships. The little boat in the film sometimes moves in surges, very much like a kayak in following seas, which would be nice except you have to expend the energy to create the following sea you are surfing.
So I presume that your bayou has a warm layer over a cold layer. Hot summer weather heats the surface layer - the earth is generally around 50 or 60 degrees, so the lower layer of the water should be about the same if conditions are calm and there has been no mixing due to wind. Apparently the interface is close enough to the underside of your kayak, so your paddling energy is going into subsurface wave formation, not into forward momentum of you and your boat.
This apparently also happens commonly in Norwegian fjords where fresh water runoff sits on top of salt water, and the high fjord walls block the wind, inhibiting mixing the stratified layers.
Here's my suggestion - take a thermometer with you on a string - when you find a stretch of dead water, stop and measure the temperature at a few depths to see if there's a jump in the top foot or two of water. Based on flatpick's statement, I'll bet there's a strong temperature jump within the top 18". By the way, internal waves would slow you down much more effectively than a shallow bottom, as waves can absorb a great deal of energy.
Cheers, Carl
Can you quantify your first statement
With actual measurements ?