Welcome to my brain. It’s messy. It’s interesting. And it’s all connected if you stick around long enough. "Believe Nothing: no matter who said it, even if I have said it, except it agree with your own reason and common sense. Siddhartha Guatamo, the Buddha.

The Physics of water

I swear to you, the physics of my favorite play ground are strange,,, especially at the ‘border’ between water and air. Things get, , , I guess ‘backwards’ would be a good word for it.

Like when rolling, the last thing (completely counter intuitive, and against all survival instincts) you want to leave the water is your head. And the way I explain it to people curious about the “Eskimo roll” : ‘your head is a 14# weight on the end of a nearly 3’ lever with the boat as the pivot. BUT, in the water your head is bouyant,,, it helps as a fulcrum.”

The reason for my ‘frustration with physics’ revolves around that new paddle I made. Took it out for its maiden voyage today, and took the old beat up, taking on water, carbon fiber model as a back up. GPS readings for the ‘out’ trip using the new paddle exlusively: 5.2 top speed, average 4.3 Hit the turn around and stowed the new paddle and used the CF Greenland for the return. Cleared the GPS and took off: 5.5 and 4.7 respectively.

WTF?!?!?! The new paddle is wider,(3 1/2″ vs 3″) slightly longer(2″) and a bit heavier(it ain’t hollow like the CF), but the boat being the same and the foils of both paddles are very close in shape (wood doesn’t get that fine edge that Carbon/epoxy layups can get) They should be damnably close in performance. NOPES,,, and I can feel the difference in the ‘bite’,,, the Wood feels ‘mushy’ where the CF really grabs the water. That difference seems to be blade thickness, not shape or size: against all reason to me.

So my questions become “does the length have more to with cadence, and does cadence make the speed?” or is this more ‘since I have been using the CF for three years, maybe its ME and muscle memory and the new paddle is tossing that a curve-ball” . And the physics of water keeps me on my toes. Water is life, but water can kill too; and like any ‘force of nature’, use reason and logic, but be prepared for the unexpected.

Good run today, 2.85 miles on each leg, plus some goofing off with waves at the point afterwards. The waves were a shambolic mess, but thats a goodness thing in my ‘training’. Had a group of seven Sea-doo riders mucking things up, but I stuck and they didn’t, since the skies were threatening off and on.

Funny that, I usually have cockpit covers on my boats when transporting, but not ‘just after’ a paddle session. I give them a chance to air out, dry out, what have you, while moving at highway speed. NOT TODAY,,,, Hit that threat of storm on the way home and Lyssa had an easy 10 gallons of water in her cockpit by the time I pulled under the carport. (I told ya, Monsoon like weather in these parts this time of year,,, It doesn’t pour, it FLUSHES) I hit that storm in Corbin, and it didn’t let up up until I was just a few miles from home. About 20-24 miles of deluge: 30′ and you can’t see the car, 100′ and you can’t see taillights. Didn’t exceed 30mph on a usual 65 section of highway. I will start to transport them like I used before I got the covers: hull up when uncovered, I could feel that 10 gallons up there sloshing around,,, Not enough to throw the truck around, but enough I could feel it,

This entry was posted on July 1, 2023 by . It was filed under Uncategorized .

2 responses

  1. Spud's avatar
    Spud

    Correct me if I’m wrong , but aren’t kayaks a displacement hull ?
    So with the same length hull , the coefficient of drag being the prime difference between each boat. That and the efficiency of the paddle design is going to factor more.

    Like

    July 2, 2023 at 6:12 am

    • diogenesoftherifle's avatar
      diogenesoftherifle

      Yes, displacement hulls (there are some WW boats that planing hulls, but only when they get the current under them, like a surfboard. I play with Seakayaks, all displacement all the time, even on waves when they are able to plane somewhat.) The whole arguement of smooth hull/rough hull goes to the linear/turbulant flow thing: some feel that a rougher surface starts a laminar flow where some of the water ‘sticks’ to the surface of the boat and acts as a friction reducer. I don’t know but I honestly think that the difference is in thousandths: not enough to be a factor under paddle power. As for the paddles, I have MUCH more to learn apparently. The foil shape on the new paddle is a mirror image of the CF paddle I own, with the exception being the fine edges: I couldn’t get the wood to take that razor like edge of the composite material. That tells me that the Greenland paddle is more a wing type paddle than an oar type propulsion unit. the face is NOT where the power comes from,,,, It can do the oar propulsion, but it reaches its peak in power as it slices, not pushes. and that makes sense when I observe the proper ‘use the core muscles’ paddle stroke and see the ‘speedo’ take off.
      In a nutshell, I will be re-working that new paddle, seeing if I can get a finer edge on the blades using composites and vacuum bagging. (or I spend the danged near 5 bills for a GearLabs paddle)

      Like

      July 2, 2023 at 6:49 am