Friday, 8 December 2017

Displacement, Weight, Capacity, and that Sinking Feeling

Recently when asked about one of my canoes and how much it will carry I responded with the numbers I usually give, the boats displacement at various sinkages. I give the displacement at three different depths. For the canoe that I am currently finishing up; if the boat is loaded to sit two inches [5 cm] down in the water it displaces 109 pounds [49 kg.] (for reference approximately, weight of boat plus large pack), at 3” [7.6 cm] it will displace 193 pounds [87 kg] (boat plus 150 lb.[68 kg] paddler), at 4” [10.2 cm] it displaces 284 pounds [129 kg].

None of these numbers tell you what the boat weighs, this boat has not been weighed yet so let’s use a nice round number that is in the right ball park, say 40 pounds [18 kg]. The canoe weighs the same in all three of the instances above, regardless of loading. Displacement varies depending on what you put in the boat, plus the boats weight. Keep this in mind when adding gear to your boat, something that those who fish seem most prone to do, every bit of gear you add subtracts from the live weight (you, passengers or fish it should carry). If a boat weighs 40 lbs.  [18 kg] you weigh, say 150 [68 kg]and you gear for a day trip, including yourself, a paddle, PFD, other safety gear and lunch weigh 7 pounds [3.2 kg], that means that a boat will need to displace 197 pounds [89 kg] to float you and your gear, you can then based on the information above see that this boat is going to float about 3” [7.6 cm] into the water.  

Displacement is simply the weight of the volume of water that the boat must push out of the way to float based on the weights as listed above, fresh water weighs 62.4 pounds per cubic foot, salt water weighs 64, or 1,000 kg/m3 for fresh and for salt water 1,024 kg/m3.  Think of it as the size of the hole you make in the lake or river, in the case of the boat in the example it is a cedar/epoxy lined hole.
To make anything float the object that is to float must displace more than it weighs plus what it is carrying, which is why a flat piece of steel sinks, but if you beat it into a boat like shape it will float. For the example above, the boat, and it does not matter what shape it takes, must displace 3.2 cubic feet (.09m3) of fresh water (3.1 of salt water) to support the load. The shape will not affect the amount of water that must be displaced the shape will affect stability and how the boat moves through the water but not the volume of water displaced.

That brings us to capacity, I use the Transport Canada method as published in TP1332E Construction Standards for Small Vessels as found in section 4.3.1.3 where the very simple method to find a canoes displacement, is the point where the vessel has 178 mm [7 inches] of freeboard, this is referred to as the ‘recommended maximum gross load’. This is measured at the lowest point of the sheerline.

Freeboard is the distance between the water and the top edge of the hull, the sheer being the top edge of the hull. That number for the boat used for illustration purposes in the first paragraph is 172 kg. [379 lbs], it is that simple, but this only applies to canoes, and yes what constitutes a canoe is defined in an earlier section of the publication one that sets the length to beam ration which changes with the canoes length, (4.25 m or less max beam 1/3 of canoe length, 4.25 to 4.9 m - 1/4 of length, over 4.9 m – 1/5 of length) additionally it sets the maximum transom width at 45% of the canoes width. Different boat types naturally have their own standards, and these are further divided based on length and whether they are over or under 6 meters [19.7’].

Another number used is the pounds per inch immersion or PPI, for those using metric terms kg/cm, the number given is based on the boat floating on its designed waterline, this is simply the waterline used in the design drawing. For the boat being used as an example it was 4” [10.2 cm] at which point the boat had a PPI of 96 pounds which is 17 kg/cm, when the boat is floating at this depth it will take 96 pounds to sink it one inch or 17 kg to sink it one centimeter. Those of you who look at the numbers in the first paragraph will notice how this does not match up with the numbers given. The reason for this is that the number changes with the shape of the hull so it will different for nearly all sinkages (unless you have a boat that is box shaped), but it does give a good indication of what happens as you load the boat. For information’s sake this boat would displace 502 kg (1100 lbs.) to the point at which the water reaches the sheer.


The above numbers show you there are some boats that are sold as power canoes that are in fact small power boats from a legislative point of view, and may have had their capacities and horsepower calculated differently. Unlike power boats the horsepower/kilowatt ratings for canoes are selected from a chart based on boat length and not found by calculation. 

Tuesday, 20 December 2016

Finding Your Balance

Many kayakers head out in their boats seeking a sense of inner balance, but those first couple trips in the spring (for those of us who have to deal with hard water winters) can be a challenge. It is not a sense of inner balance that’s missing its actual physical balance that is missing, the transition from the office chair to the kayak seat can be interesting due to the kayak having significantly less stability. There is a simple way to eliminate this and that is the use of a balance stool, these can be constructed to challenge any paddler by increasing the rocker in the stools base. This is also a good project for anyone thinking of buying or building a kayak why not be ready when the boat hits the water, no surprises, look like you have done it before, from day one.

This blog is also written for those who have experience only in rental and other kayaks that are short, fat, and where choosen for their job because they where completey suited to an application where the majority of users have no experience whatsoever in a kayak. The change is then made from a boat which is 30+ inches [76cm] wide with a flat bottom to a rounded, or V bottom boat, that is 23" [58cm] wide and find that there is a significant difference in stability, that they were not entirely prepared for, with the stool you can be ready. If you find yourself in this state don't be discouraged if it takes a few attempts, much more comfortable in the denon the stoool than on the water in the spring. 

Think of it as a rocking horse for adults, and best of all it is simple to construct,inexpensive and can be constructed in a half hour, and requires few tools, a jig or band saw, six screws, a square, and eight feet of 2x 8. If you make your stool 2” [50mm] shorter than I did you will only need six feet of 2x8, the length will depend on how tall you are, what is the distance from the back of the seat in your boat to the foot pegs this will guide you as to the required length. (My stool is 50” [127cm] long and I am 6’ 3” [1.905m] tall as a guide if your boat is not close by) When looking for a suitable piece of lumber look for one that has no big knots or faults, particularly in the longitudinal, you really don’t want it to break if you are sitting in the middle of the stool, and it is easier to cut smooth curves for the rockers if you are not contending with knots.  

Cut the 2x 8 into three pieces, two pieces 12” [ 30.5cm] long for the rockers, and a longer piece to suit you for the top. The two pieces for the rockers need to be laid out with a notch on top to accept the longitudinal piece and have the bottoms curved to make the stool unstable. The stool in the pictures has a 1.5” [3.8 cm] in the bottom you can always increase the curve later to increase the challenge or until it feels like your boat or even a little less stable than your boat to really challenge yourself. Note how I drew the curve a ¼” [6mm] up from the bottom, this is to help ensure a smooth curve on the bottom of the rockers, a flat spot would defeat the purpose of the stool, and cutting close to the edge makes it easy for the saw to break out of the wood leaving a small flat on the bottom.

Layout the curve on the bottom by marking the centreline on the 12” [30.5cm] pieces and put a mark up each edge 1 ¾” [4.5cm] up the edges, join these marks to form a smooth curve, with a batten. The batten can be anything that is smooth, straight, and flexible, hold the batten so it touches the marks on the sides and pull the centre down to the bottom line and draw in the curve. This task will be easier with some one to help hold the batten. 

The notch on top needs to match the 2 x8 mark half the width to each side of centre and the depth of the 2x8 then draw in the notch, all that’s left is to cut the two pieces for the rockers. As always when you cut; cut on the waste side of the line this should give you a nice tight fit in the notch.

Assemble the three pieces, making sure the end rockers are square to the centre longitudinal. Join the two pieces using three-inch-long #10 or 12 screws, with the heads countersunk into the longitudinal.

If you are new to kayaking the first step is to simply get used to balancing yourself, it will not likely take long. Once you get used to that try turning your upper body as if you where checking out what that paddler just behind you is up to or you wanted to make yourself heard when speaking to them by turning in their direction. The next step is to grab a broom or length of dowelling and go through the motion of paddling, now you are on your way to finding the outward balance so you can concentrate on finding some inward quiet and balance.








Monday, 2 May 2016

Class Time


We have been looking at the possibility of offering classes to help those who want to build a boat but would prefer to do so with some guidance. After some serious searching, finding space that would allow us to do so economically has proven that if we were to follow the same model others are using that doing so would be difficult.

This has led to a new line of thought, I have the shop which houses my office and which I use to build the prototypes for our new models, while it is not large but is sufficient to build one boat at a time. Interested in taking a class on an individual basis, one instructor and a builder with a helper if so desired?

This approach has some advantages, you do not need to purchase tools you may never use again, the focus is only on the boat you are building, and you don’t have to wait until the boat you are interested in building is being offered in a classroom setting somewhere. The class you book is your class alone, building the boat you want, this offers you much more flexibility when it comes to timing as you do not need to wait for six or eight like minded individuals.

 Another advantage, we will be able to offer in this setting is we can customize a design to suit your needs, or you can have a custom design drawn and then come here to put it together. We may even have what you are looking for drawn in the computer and just have not had time to build that particular model to date. This is something that is not possible to do in a class setting. There will in these cases be a design fee but these will be kept to a minimum as full plans and building manuals will not need to be developed as we will construct the boat together.

Taking a look at the courses being offered here in Canada, which are often offered in conjunction with US firms, in US dollars and with a slightly higher tuition rate than the same course in the US. As I write this with the current exchange rate tuition is $850 US which is $1102 CAD. In addition to which they charge $200 US for shipping which equals $259 CAD. for a total of $ 1361 CAD. , there is also a charge of $450 US for a helper which equals $584 CAD. if you bring a helper the total comes to $1945 CAD.  In addition to this these courses require you to supply some of your own tools, some tools you will need to finish and care your boat in the future so you will need to buy these, others for many will be a onetime purchase such as the forty clamps recommended. These prices are in addition to the cost of the kit which in the case of the US providers is in US dollars, ours are in Canadian dollars resulting in further savings for you. If you are wondering the taxation will be the same as the courses are taking place in Canada.

The big question is then naturally course cost, a one on one course will be offered at $1,000 CAD and a course with a helper at $1400 CAD. These prices coupled with our much lower shipping costs (normally less than $100 CAD) coupled with the costing of our kits in Canadian dollars gives you the opportunity to build a boat at less cost and with more flexibility in timing than you can get with our competitors.

Should you know what you would like to build, and when, send us an e-mail and we can discuss the specifics of setting up a course for you. Not sure which boat you wish to build contact us and we can discuss the possibilities.


For our US friends as mentioned on the web site we are just a few minutes down the river from the Sarnia/Port Huron border crossing and about the same distance up river from the Sombra/Marine City ferry crossing. As this is written based on the exchange rate today tuition is just $772 US with one builder and $1080 with a helper.

Friday, 12 February 2016

Splashing About In The Pool


This is not a series of thoughts about hitting the local pool in winter to learn new skills but rather spending time splashing about in the pool of learning and the feeling that you are slipping under. At the end of this note I will get back around to boats and building them, please bear with me as I wander in that direction.

Last year just as I was thinking about having the web site updated, the company that looked after my site folded and they did a good job of making sure the site stayed up and transferring it to a new host. The issues that arose where from the fact that the original company not only hosted the site, but looked after its content based on the information I supplied them in order to update it. The issues only came to light after a summer of designing and building new models preparing the plans, writing new content, and then contacting the new host to be told that they don’t look after content, just hosting.

Back to the pool, it’s at times like that where you suddenly realize that all the work you have put in, making you think that you were headed somewhere, was illusory. It turns out that in fact you where treading water, suspended, going nowhere, working hard but not making any progress.

The good thing about this was it gave me more reason to rethink the site and how it works. Over the years the site has been in existence one thing I always wanted was for it to be more responsive, to be able to alter it without having to write the content then pass it along and wait till it was my turn to have the updates installed. I also wanted it to be more user friendly, with our association with Noah’s you needed to get off my site and go to theirs to place a kit order, not real convenient.
With the new site the idea is to link each of the boats to the appropriate page on their site so you simply click the link and go directly to the page that contains the ordering information on their site. This should make it seem to be essentially one big site where everything you need is just a click away. To achieve this I decided to build the site with new content myself, this would leave me with all the files and the ability to modify the site in a timelier manner. 

What makes this possible is the use of a WYSIWIG (what you see is what you get) site builder which means you do not need to be able to write computer code to build your site but for the most part you simply type in what you want. This by the way only works to a certain extent as you need at times when using things like Pay Pal or links to other sites to insert their code into your site to make them functional. Even this simple method of building a site at times has left me feeling like I was back in the pool, definitively in the deep end and floundering badly. I am sure the company that hosts the site must have when answering some of my newbie questions wondered how I even managed to turn the computer on in the morning.

Writing this has led me to think about the boats, their plan sets their construction and how easy it is to assume things which can leave others floundering. One of the things I noticed while going through this process was how in all our fields we tend to forget that those who are learning and those with no or limited exposure to what it is we do have no idea what some of the terminology and short forms we tend to use mean.

I guess what I am really trying to say is this dip in the pool has not been a bad thing, besides the expansion of my understanding of the electronic world, I will try to keep in mind what this experience has been like when plan sets are put together. If you are building from our plans and you think I am assuming knowledge you don’t have send us a note, it will make not only the process easier for you it may help clarify things for someone else down the road.

Wednesday, 18 November 2015

Massasauga 12

The Massasauga 12 is a hybrid design in that it has a stitch and glue type hull with a single chine and a cedar strip deck. The boat has more beam than many of our other designs of this length to allow for more capacity to help more paddlers fit the deck has more camber than the boats with a plywood deck. The shorter length allows more versatility when it comes to storage but with enough capacity to allow for short trips.

The hull is constructed using the boats bulkheads to help form the hull shape while the panels are stitched and glued together, the hull with the bulkheads is then used a mold for the construction of the deck. The use of a cedar strip deck allows for more individuality in the construction of the boat as well as being a simple method to increase the leg room in the cockpit of the boat. This method of construction also allows you to build a boat that is a little more special than an all plywood model.


The capacity listed on the flyer is as noted at the 3” (75mm) waterline, which is the waterline shown in the sections behind the boats data. As is our practice included in the data is the PPI number which is the pounds per inch immersion which is the weight required to sink the boat one inch deeper in the water from the designed waterline this will give you an idea of what will happen with the boat when you load it with gear and if you are a heavier or lighter than the capacity listed.

Friday, 13 November 2015

Vuntut 12

Over the past year we have developed five new boat models the first of which was the Vuntut 12 which is a pack canoe designed to be propelled by a double paddle. As soon as it was launched it proved to be a great boat to paddle with the result that it was my choice of boat over the summer, that is until someone else came to the same conclusion and as a result the prototype was sold before the summer was over.

The name of the boat is a Gwitchin word that means among the lakes which seemed very appropriate for a boat made to journey. The boat has enough capacity to allow most paddlers to head out with a pack and allow them to get away from it all.

The boat is constructed using cedar strips over molds placed on a strong back with a laminated stem and stern.

There are a number of options when it comes to glassing the boat, the standard option is to build it using a 6 oz. exterior cloth and a 4 oz interior cloth sheathing, the second option is 6 oz. both inside and out.  The third option is to use the same build as the prototype which was 6 oz. carbon twill inside and 6 oz e-glass outside, the first option listed comes standard with the kit. The carbon was done as an experiment rather than a necessity as a test looking forward to other possible lighter builds in the future.

One of the great advantages of a pack canoe is portability, when portaging this canoe during its trials I could simply put the boat over my shoulder my pack on my back and set out down the trail.

For plans, or complete boats contact us and for kits you can contact either us or Noah’s Marine.


At the present time we have begun the build of a 10’ version of the canoe.


Tuesday, 10 November 2015

A Toy Story

I have been thinking more about my chosen field and how it operates; much of this has come about as a result of looking at ‘green’ or environmentally friendly ways of boat building. I will begin by saying that I have no illusions about the importance of what I do, when asked what I do sometimes my response is that I design and build toys, because that is what I do. It does not matter if the boat is eight feet long or three hundred and eight if it is not a working boat it is a toy, this fact is important when you look at the idea of green boats. In a forum that I check in on regularly someone recently commented that the only truly green boat is one that you do not build, since it is only a toy and therefore there is no real imperative reason to build one.

Every time I see an article about the latest mega yacht being built and the efforts taken to make the project ‘green’ I have to chuckle. Beyond the fact that the boat or yacht is for pleasure only and therefore a toy, once the vessel has reached the point where it will do its job and hold the people it was designed to carry the rest is excess and can’t possibly be ‘green’, it exists only because it can be afforded by the owner. Many of these mega boats where designed with the capability to cross oceans, if they do a crossing it will likely do so only with a small crew on board with the owner joining it when it reaches its destination, meaning in the end it is only a floating hotel. Some do not even do that much and are shipped across oceans as deck cargo or in a ship designed for the purpose, yes they do exist.

This does not let the rest of us off the hook, in Canada we celebrate a small boat, the canoe but the canoe we celebrate is not the toy we use today but a workhorse designed to convey people and goods from one place to another in a world without roads. The footprint for an individual canoe may not be as large as mega yacht, but with the numbers of them out there they still leave a sizable footprint on our world. This really rings true when you consider the number of them wasting away in backyards or serving as a planter in a garden.

The previous paragraph does not mean that I have come to believe that we need to take up our place on the couch and remain there. We do need to get outside it is good for the body, the soul and helps form or should, a connection with the world we live in which is good for all.

It does mean that no matter how careful we are, manufacturing the craft we use requires resources, as do the trails that we find in the many parks that allow us access but we often give little thought to. These are maintained by someone who may have been flown in to do so that is also our footprint, as are the trees cut to make that trail. Our fascination with light weight gear is also a place where there is little green involved (except for that which we part with to purchase it) many light weight fibers are the result of the use modern high-tech production and research methods.

This does not mean that I am giving up on boats and the outdoors, I love being on the water and helping others get out there in boats they have built, and I will continue to research ‘green’ materials. What it does mean is that I don’t want to fool myself by thinking what I do is ‘green’ but I do want to make sure that what I do is done using materials that do the job as efficiently as possible and are as far as possible made of materials that are sustainable. Even that last statement I know could lead to a discussion on what is meant by efficiency.

Keep getting outside just remember, as you look around and enjoy the world in which you travel to look behind to consider the footprint you have left, it is there no matter how lightly you tread.