Dragon Boat West

At Gorge we got to practice being good losers to a Junior team ( they handed us an economy sized box of whoop-ass) Now I definitely don't remember any calculus or physics but there must be an equation that shows the weight of a boat load of 80 lb paddlers against a group of 170 lb paddlers. Obviously there must be a point where a lighter loaded boat with fewer paddlers would beat a heavier fully loaded boat. This is just an enquiring minds type of question. Can anyone help me out here.

Lighter paddlers = less portion of the boat in the water = less friction = faster

I am horrible at physics but just be reasonable. If the team is fit they should be able to "pull their own weight" and then some.

I agree but my little non- scientific mind wants to know more and this mathematical challenge happens so rarely for me, I feel compelled to explore it

I think I was a bit off when I read and posted earlier. I was in mid-celebration here in Tampa and for some reason the first thing I did was go on DBW and answer your post with my cup right there beside me.

Not that it's much different now, but lets just say that it's easier to lift a boat and get it to a max speed if it's lighter. If the power is there then great, (eg. Team China) this is good for short distances.

Longer distances, eg. 500m-1k aren't as reliant on getting the boat up to speed, as it is about power endurance. Power muscles are generally hypertrophied so the people are heavier (thus why power athletes are jacked... football, Olympic lifting, sprinting, etc.)

In essence for this sport, you want to be as powerful and as lean as possible.

Sorry I'm still a bit tipsy. I';ll try to remember to read this later

Hey Manda
i have emailed you some equations in a pdf file , 5 pages just to explain why a lighter boat can go faster,
Selltiles i could not find an email address for you but if you want to pm me with your contact info i can send it to you as well
Ian

This site should answer most of your questions.  It certainly helped my understanding.

http://www.atm.ox.ac.uk/rowing/physics/weight.html (http://www.atm.ox.ac.uk/rowing/physics/weight.html)

Thanks NewDragons for that website.

So whoever can pull horizontally the paddle the furthest with effective strength and most often with the least amount of drag will have the greatest work (W=F*d). So positive and negative blade angles will have to subtrace sine of the angle, longer the reach more further pull, white water (bubbles) reduces force (Reynold's number) and more strokes mean more pulls.  Hurray.

So where's the drag? The more massive the boat, the greater the displacement. That means drag from cross-section of the boat in the water and the surface area in contact with the water.  Lighter teams wins.

As for the distance. In short distance races, the anaerobic team wins, so a bunch of weightlifters would win on the strength side because anaerobic muscle produces more strength than aerobic muscles; however, in long distance races, anaerobic strength is reduced and aerobic strength becomes more effective. So long-distance runner should do well.

So a group of massive and fat paddlers could blow away skinny lean team in short distances, but the lean team would win in long distance.  Okay. 

Then why does that seem to be the opposite of what I have seen?

Yes, I am interested as well.

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The website was prepared by Anu Dudhia ([email protected]) from Oxford University Atmospheric, Oceanic and Planetary Physics, also an ARA Silver Level coach and surprisingly slow sculler from St Catherine's College BC.

You can't discount other factors though like stroke rate, timing or technique.  Junior teams often have quite high stroke rates and energy to spare!

Also, whether you're heavy or light, if you're just moving surface water your contribution is diminished anyway.

I'm just trying to picture all these "massive and fat paddlers" cramming in a dragon boat!  Don't imagine the front or back would be much fun!

Leverage is also an important factor.  If you are taller, one can move a large boat with more ease. Rowing is a good example where taller people perform well.  

All the points on size is not important in my opinion when it comes to dragon boating.  To get faster, practice is the solution, no matter who is on the team.  Timing together and time on the water will help the team the best.  Small boat training can greatly help people 'feel' the water better, and knowing how to move a solo boat well is the greatest factor in how well a person can paddle.  Other factors add to that as well, like fitness, the person's height and so on, but time on the water and knowing how to move the boat, then coming together and knowing how to work together with ones dragon boat crew is the greatest difference.

All other things being equal (experience, training etc) between two teams , with the exception of weight, the heavier team (with more mass) will require more energy to keep pace with the lighter team.  This is in accord with the laws of physics as they relate to overcoming initial inertia , accelerating  and maintaining a greater mass at speed...simple.

However, this is not to suggest that the lighter team will always win because there are other factors at play.
1. What form does the extra weight take -and does the extra weight contribute to greater initial power and more sustained power at speed?  For example, if the weight is evenly distributed over the crew in the form of extra muscle and some extra body fat then the weight could be making a contribution.  On the other hand if excessive weight is concentrated in a few individuals in the form of fat or bone(exceptionally overweight, tall or heavy boned) then the weight is not contributory and may also result in boat imbalances/inefficiencies.
2. If the extra weight is largely muscle mass - as in a mature competitive team - then the extra muscle, assuming it is in the core and upper body, should provide greater anaerobic capacity allowing for more sustained high rate paddling.
3. When you place a boat full of people in the water, the water displaced by the boat will weigh precisely the same and the boat and people (Bernouilli?) so the heavier team/boat will have a greater wetted surface because it sits lower in the water -and more friction.  It also has a greater weight of water it has to push out of the way as it moves through the water - more fluid resistance.  On the other hand the heavier team may experience less boat oscillation (especially in lighter boats - BUKs) as they paddle which should theoretically be more efficient.

Whats the answer - I don't know but it should be a good subject for a PHD thesis. Rob is right - work on water time.

Cool--I knew you people could come up with an explanation. Looking for tall, skinny paddlers with great upperbody strength

You don't want skinny, you want big muscles on those tall frames.

Interesting article here:

http://www.nytimes.com/2007/09/27/health/nutrition/27Best.html (http://www.nytimes.com/2007/09/27/health/nutrition/27Best.html)

A couple of paragraphs (it talks about rowing, but I'm sure same applies for dragonboat/kayak/outrigger)

At first glance, a big rower (and elite male rowers can weigh as much as 250 pounds) may seem to be at a disadvantage trying to row hard enough to push a boat through the water. But because water buoys the boat, weight becomes less of an issue compared with the enormous benefits of having strong muscles.

Their bigger muscles allow bigger people to use more oxygen, giving them more power. It’s like having a bigger motor, Dr. Secher said. Bigger muscles, with their larger cross-section, also are stronger. And bigger muscles can store more glycogen, their fuel for short intense spurts.

The same reasoning explains why elite swimmers are big. Great male swimmers often are 6 feet 4 inches tall, and muscular. And because of the advantage that large muscles give for sprints over short distances, the shorter the distance an athlete must swim, the greater the advantage it is to be big.

The bi

I found this article which relates to paddling (C1 sprint canoe), and not rowing:

http://www.surfski.info/images/stories/2009/06/science/The%20Science%20of%20Paddling%2C%20Pt.%201.pdf (http://www.surfski.info/images/stories/2009/06/science/The%20Science%20of%20Paddling%2C%20Pt.%201.pdf)