The PaddleWise Discussion on Flat Decks vs Upswept Ends

Date: Wed, 30 Dec 1998 09:55:19 -0500
From: "Gary Tabor" 
Subject: [Paddlewise] Flat deck versus upswept ends

OK ... I got thoroughly zoomed on the ballast rocks thing, so why not =
get right back on the bicycle ...

What's up with the Greenland style boat?  Why would anyone put those =
upswept bows and sterns into a quartering wind?  Wouldn't it be a better =
world with an Inuit style boat with cambered deck to convince the water =
to run off?

Does one go Greenland when large waves are the concern and Inuit when =
wind is the rub?

Gary Tabor

Date: Wed, 30 Dec 1998 09:59:30 -0800 From: pid (Product Information Department) Subject: Re: [Paddlewise] Flat deck versus upswept ends Ah well, Gary, it's a rite of passage, like the ugly things they do to people when they cross the Equator for the first time. Well done keeping your sense of humour about it all. I haven't paddled a lot of "Greenland" style boats, but here's my understanding of why they are that way. The upswept bow and stern provide a lot of "reserve buoyancy" so that the bow or stern will not sink surfing down a wave, while at the same time not increasing the usual waterline width of the boat. Although I don't believe it was the primary purpose, people also point out that they tend to make the boat unstable upside down, so that it is partially set up for a roll (great, so long as you can roll on both sides!) I understand that if properly designed, the bow and stern windage offset one another, so the boat does not weathercock etc. The professional designers on the list will no doubt expand and correct this explanation. Cheers, Philip T.
Date: Wed, 30 Dec 1998 17:13:47 -0500 From: "John Winters" Subject: Re: [Paddlewise] Flat deck versus upswept ends First, the Greenland Inuit built a number of different styles. The upswept ends characterise the West Greenland style of boat but even they did not always have the degree of upsweep that many associate with "Greenland" kayaks. For example, I have lines from a 17th Century West Greenland kayak with a pretty but relatively flat sheer. East Greenland and Polar Greenland Inuit did not use the high upswept ends. To find out why the West Greenland Inuit built their boats that way you would have to ask them. Unfortunately the ones who started it all are now long dead. Nothing in my research suggests more than aesthetic preference for the more extreme examples. My experience with this type of boat reveals nothing that would make the boats particularly difficult to paddle in wind if the hulls have the proper shape. Keep in mind that the hydrostatic forces greatly exceed any aerodynamic forces. Paddlers often attribute a boat's failings to those attributes they can see. More often than not the reason for a boat's good or bad behaviour involves something far more complex and not always obvious. The ends sticking up do have an effect but only a trivial one compared to the hull shape. Would the world be better without the West Greenland boats? Who knows. Would it be better without Brunettes or Redheads or people with brown eyes? Would it be better without Jackson Pollack, rap, disco etc.? Beats me. As for water running off, very few kayaks spend much time dead level so the water has ample opportunity to run off the heeled deck even when flat. It might run off a cambered deck more easily but this is a relative thing. Is more better? Maybe not. Maybe so. Depends on how important it is to the paddler. It doesn't bother me but I still camber the boats I design because they are stronger that way and prettier (to my mind). P.S. Do not get the idea that ballast rocks are a hoax. Ballast has been proven by all paddlers to be the best way to improve stability and seaworthiness on boats of all types. For an excellent example of the value of ballast read Hannes Lindemann's "Alone at Sea". On his first crossing of the Atlantic his ballasted Liberia II did not capsize. On his second crossing his unballasted kayak did capsize when his sea anchor failed. It also appears that the Inuit often used crude ballast rocks in their kayaks. My Genuine Canadian Ballast Rocks (TM) simply happen to be the most advanced ballast system available today. I cannot, however, take credit for the idea since rock ballast has been used since the beginning of recorded history. The Sumerian poet Dingiraddamu mentions ballast rocks in his poem mourning the raped goddess of Lagash: In the holy city Girsu the children are in distress. In the harbours our ships lie upside down, their rocks on the sea floor. The invaders lay waste to our fields and the Temples are burned. Oh Lady of my city, desolated, when wilt thou return? I wept when I first read this lament. So, do not be misled by those who treat sea kayak safety in a cavalier manner and put their trust in rolling and paddle floats. Better to not capsize at all than to hope for the best while water runs into ones ears and nose rotting the brain and obstructing the flow of psychic energy. Cheers, John Winters Redwing Designs Specialists in Human Powered Watercraft