So I actually built something quite similar (same materials, different plans) about five years back. Great experience and a lot of fun to paddle around in the nearby marshlands.
All told I spent just over $100 and the project took about 2 long weekends. I used fiberglass to cover the exterior and the boat is still in great shape today (though sadly underused).
Thank you, point taken. Speaking of constraints, the concrete canoe competition held by the American Society of Civil Engineers shows that concrete is not really a constraint. Also, it would be interesting to see if you could repurpose Ikea furniture and make a boat.
I have always had a fascination with the concrete canoe competitions.
Looking at the 1st place PDF for the UNR team, and the admixture they have come up with; I have always wondered if AeroGel would be a suitable additive to the mixture in place of some of the other components.
AeroGel would additionally replace the glass aggregates mentioned in the PDF as well.
For example, they use polyvinyl fibers to add durability and flexibility to the mixture, as well as some other pre-stressing substance known as Komponent, which I am not familiar with.
I have always thought that it would be interesting to add powdered, or fibrous (if it exists) AeroGel to concrete for both insulating purposes (in the non-concrete-canoe use case) and weight reduction (canoe centric).
Additionally, once a fairly cheap, abundant source of carbon nanotube fibers could be procured - adding this to the mix as admixture to provide for strength and flexibility would be great. (I don't have access to either materials - so this is all speculative with respect to practicality.)
It is not that contrived of a constraint. My dad built two rowboats for my brother and I when we were young kids. Each one was built out of a single piece of plywood. Marine grade plywood is expensive, $40 a sheet I think, so the difference between one sheet and two sheets is significant.
It's neither. In the Mid-Atlantic (New Jersey and the Chesapeake Bay) that would be a ducking skiff - a narrow, flat bottomed boat with lots of rocker. It is paddled, rather than rowed, because of its narrowness, but it's still a skiff. They've been around a long time, my father taught me to build one back in the 1970s - like this one out of plywood, but he said they used to be made out of 1/2 inch white pine.
<more pedantic>
In some parts of the world, such as the United Kingdom, kayaks are considered a subtype of canoes. Continental European and British canoeing clubs and associations of the 19th Century used craft similar to kayaks, but referred to them as canoes. This explains the naming of the International and National Governing bodies of the sport of Canoeing.</more pedantic>
<less pedantic>A kayak is a decked boat that one sits in with one's legs extended. A canoe has no deck and one kneels or sits on a seat.</less pedantic>
There are also "closed canoes" that are decked like kayaks but deeper hulled, and you kneel like regular canoes. I had a room-mate that used one in competition.
I'm just curious, what characteristics of this boat make it a kayak and not a canoe? He seems to call it both and some of the indigenous "canoes" look very similar.
<canadian-pedantic>A kayak is longer and thinner and lower to the water and is often covered. A kayak is typically paddled using a double ended paddle. In Canada, the boat in the article is a kayak; I don't think anyone here would call that a canoe. A canoe is deeper, wider and fatter (like some Canadians perhaps ;). A canoe can transport a lot of cargo but is also light enough to carry across portages. Many years ago native people and fur traders could travel entirely across Canada in a canoe. Some people still attempt this feat.
In other parts of the world the boat in the article might be considered a canoe, but I would say not in Canada.
</canadian-pedantic>
"A canoe is deeper, wider and fatter (like some Canadians perhaps ;)"
Not sure about Finland (where the article's author lives), but a wide, fat open canoe is actually called "a Canadian" in many parts of northern Europe.
The concept of an "open kayak" sounds pretty confused, though, given how they were originally built (skins wrapped around a thin wooden frame) and used (coastal sea regions, including the open sea).
All told I spent just over $100 and the project took about 2 long weekends. I used fiberglass to cover the exterior and the boat is still in great shape today (though sadly underused).