Paddling Perspectives:
Your Cosmic Paddling Questions Answered
July 2020
by Kent Walters
AUTHOR’S NOTE: This column is intended to be funny at the expense of truth and accuracy, but I sneak in some good information as well. It is up to the reader to distinguish between entertainment and reality.
NEED MORE AUDIENCE PARTICIPATION – PLEASE SEND QUESTIONS TO: kentwalters@gmail.com
Q: What is an apple snail?
A1: This is a variety of snail that subsists on apples, which is why we don’t see too many of them around here. This is a not-too-distant relative of the molluscivores described in the April newsletter HERE.
A2: This is a variety of mollusk that is about the size of an apple, and has many subspecies, such as MacIntosh, Fuji, Pippin, Honeycrisp and Granny.
A3: This is a serious invasive aquatic snail with some unique properties that endow it with excessive survival skills. For example, it can process oxygen through gills or a lung-like structure, allowing it to breathe underwater or above water, or above water from under water through a siphon. It can float, sink, dig and climb. And those are just a few of the tools in its survival arsenal. Well, my friends, ya got trouble . . .
(Substitute “apple snails’ for “pool table” HERE)
FACT CHECK: Link to HERE for more information (I’m making it easy for you):
Q: What is a “strainer”?
A: This is when something is coming up ahead that requires you to paddle hard (strain) to be in the right position when you get to it. For example, if one of your paddling buddies says, “Hey, hurry up so you can see this osprey ripping up a fish!”, and you pour it on (pull a strainer) to get there in time to watch it finishing off its meal. Sometimes you need to execute a strainer to get around a log that suddenly appears in your path before the current sucks you under it (hint). David Portz is using strainers when beaching his boat or seeing how big of a wake he can generate in his Rip10 (see photo above).
Q: How far does a paddle travel in the water during a typical single forward stroke when you are paddling “steady state” (maintaining a sustainable velocity)?
A: Not very far. I’m going to guess about 6” based on non-scientific observation, but how should I know? This is a question for someone like Daniel Roy, who can pencil it out (reverse-engineer f=ma, assuming 100kg for paddler, boat and gear maintaining 6km/hr on flat water, with some finagling for paddle power face size / shape, water density, torque, temperature and depth of the water, etc.) and reply to me. I will redistribute his response in the next installment. (The gauntlet has been thrown for audience participation.)
Here is some discussion about a forward canoe stroke, but it never hints at paddle travel: Physics
Here is an excellent discussion of how a kayak paddle works, including allowances for cavitation losses, which also ignores the pivotal question of how far the paddle travels: how a paddle works.
Q: Who has the best kayak in the Houston Canoe Club?
A1: Since this is a canoe club, does it really matter?
A2: That would be me and Bruce, and with no close contenders I humbly submit, after my extensive, personal and objective experience with many kayak types and brands.
A3: That depends on what kind of water you like to paddle, and your own personal preferences.
A4: It could be any of us, except anyone who has a “Hello Kitty” decal on his/her kayak.
Q: Why is it more difficult to paddle fast in shallow water (causes a strainer)?
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| Froude |
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Bernoulli |
A1: Duh! Your hull hits the bottom.
A2: When the water depth becomes less than ¼ of the length of your waterline, Froude and Bernoulli created laws that put up a lot of resistance to your hull’s movement through the water. At least you know who to blame . . . and I have graciously provided their pictures in case you need a new target for your dart board.
Q: What is the most intimidating creature you have observed in your many expeditions?
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A: Without doubt, the most fearsome creature I have ever observed in the wild is the Peruvian Wooly Egret. A full-grown male (see photo above) stands over 15 feet tall and has a wingspan of over 25 feet. This amazing carnivore has evolved to apex predator status, and observing one in action leaves little doubt as to its deserved ranking in the food chain. The strength of its skull-crushing beak combined with its lightning-fast strikes are the stuff of nightmares. As Frank Ohrt can testify from his forays into the wild rivers of Peru, these descendants of the pterodactyl lurk in the foliage along the banks of rivers, hiding behind trees because of their unfortunate white coloring that did not evolve to camouflage them with their surroundings. The woolly egret favors hunting sites near rapids, where distracted kayakers are busy reading the water in front of them. When the kayaker is fully engaged in planning his next stroke, this giant bird will leap from the bank and impale him, after which he retreats to the forest with his fresh kill. Back in the forest, is a simple matter for the woolly egret to push the kayaker off his beak with his articulated foot and separate the kayaker from his kayak and helmet. NOTE: helmets have little effect on the ultimate outcome of an encounter with a woolly egret.
OVERHEARD . . .
MUG O’ THE MONTH:
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| The author, Kent Walters |