I am replacing the gunwales on my old MR Explorer RX. It had the IQ system gunwales with the removable/adjustable seats.
I am adding wood yoke to center. Where should the new wooden seats be positioned? My “calculations” are the center of the stern seat at about 3 feet (~20% of length) forward of the stern.
The bow seat at 10.5 feet (~66%) forward of stern. Does this sound about right?
Thanks for any thoughts!
cc
I recently found this schematic for the Mad River Explorer. This is for Royalex with wood gunwales.
https://www.harmonygear.com/boatparts/viewpdf/filename/schematics_mr_explorer.pdf
You don’t necessarily have to place the seats in the “stock” position. Where you place them depends on how you plan to be using the canoe, and who you plan to paddle it with.
The more distance you have between seats, the more room you have to carry gear which may or may not be an issue. Other constraints are how close you can physically position the stern seat to the stern stem and how much leg room you want or need for the bow paddler.
In my experience, many tandem canoes are set up stock to be trimmed significantly bow light. This is probably better than taking a chance on them becoming trimmed bow heavy as a result of a big discrepancy in paddler weights, but most are more bow light than I prefer. The MRC 16 foot Explorer is no exception. My Explorer is a Kevlar version, but I think that the Royalex version has seats similarly positioned.
In your case, a position of the stern seat center 36" from the stern stem sounds awfully far aft. The Explorer does have fairly full ends, but I would question whether the width of your rear seat seating surface will allow you to fit it between the sides of the hull that far back. If it does, consider whether this position will allow you a comfortable degree of leeway between the gunwales to fit your body, or the body of the likely stern paddler. Keep in mind that the distance from the front of the front seat frame to the rear of the rear seat frame of the typical wooden frame canoe seat is only some 9 1/2" give or take a smidgen. The typical width of the seating surface is around 12-13", but sadly the rear end of many a modern paddler will extend beyond that by an inch or more on either side.
I usually start by deciding how much leg room is required for the bow paddler. The distance aft that the bow seat needs to be placed is usually determined by this factor. I also figure that for the average paddler in an upright seated position, the body center of gravity typically winds up to be around an inch and a half in front of the front edge of the seat frame. The paddler’s center of gravity will depend on how they sit on the seat, how much they stretch out their legs, and if they lean forward the COG will of course shift forward a bit.
Once you determine your bow seat position, you can decide where to place the stern seat. If you anticipate paddlers of roughly the same weight, and you want the boat trimmed neutrally, measure the distance of the front seat frame from center, add 1 1/2", measure that distance aft from center, and place the front of the rear seat frame 1 1/2" further aft. If you anticipate the stern paddler being significantly heavier than the bow paddler, you may wish to position the stern seat further forward. If you want the boat to be a bit bow light, you can shift it a bit aft.
As an example, given the schematic referenced by RLS assuming a 16 foot explorer, the very front of the front seat frame from center in the stock position is 38.5" and the front edge of the front frame for the rear seat is 50.5". If you use my rule of the paddler center of gravity being roughly 1 1/2" forward of the front edge of the seat frame, the bow paddler COG will be 40" from center and the stern paddler COG will be 49" from center. The stern paddler’s COG being farther from center, the boat will trim bow light for paddlers of equal weight, which is exactly my experience for that particular boat (and many others).
If you want the boat trimmed closer to neutral for paddlers of roughly equal weight, you can either move the front seat further forward (as the requirement for paddler leg room allows) or the rear seat further forward, or a combination of both. Moving the rear seat forward is usually easy to do but will diminish somewhat the space available to stow gear.
RLS thanks for the link.
PBLANC - thanks for the detailed info! I will have to study on that. Hope to get the gunwales on later this week.
Blue Skies!
cc
If you are going to be paddling the Explorer solo, that would be also be a reason to move the bow seat a little bit further towards the center, and paddle from the bow seat facing the stern when paddling solo. Just another variable to account for. It really is a matter of taking in the variables. Since you are replacing the gunwales and if replacing the seats also you have the freedom to move things about a some. If you are reusing the seats then the current width of the seats may limit your options. Just a suggestion… If you have a regular paddling partner… take the boat to a calm body of water. Before mounting the seats, place overturned plastic “milk” grates (or any suitable plastic box) in the boat and position them with the paddlers for the best trim and make note of the position. You can put a little bit of water in the bilge of the canoe to see how much it runs to the bow or stern as a guide for the trim. Or if you have an observer on shore you can put a piece of tape on the outside near the bow and stern equal distance up the sides. You could lay the boat on a flat surface and use a piece of 2x4 as a measurement aid and place the tape on the hull just above the top of the 2x4 and the observer can tell you when you are trimmed by observing the relative position of the bow/stern tape marks to the water surface. You could use the diagram I linked above as starting point and adjust from there. If you are close on trim, you can always adjust some by placement of gear, but if there are significant difference in paddlers weight, you can take this opportunity to tune the trim some by the seat placement.
Hey campcrafter. You can also get a solid estimate (and another reference point) by just scaling the distance off a picture from the Internet. Find a plan view picture of a Royalex Explorer and make it as big as your screen allows. Measure the distance in millimeters from bow tip to front edge of front seat and rear seat. Measure overall boat length in mm. Then just take the fractions, for example bow tip to front seat edge divided by overall length (in mm from a picture) times your actual real life boat length in inches tells you where the front edge of the front seat should be. Make sense?
Float the boat empty in a pool or calm water. Take some 2" wide tape and put it on the sides of the hull so that the bottom edge of the tape is right at the water line. In this state the boat will be in completely neutral trim. Then get in the boat and reposition paddler(s) and load while an observer checks the tape. When an equal amount of tape shows above water at the bow and stern the boat will again be in neutral trim.
Trying to measure an equal distance up the hull from the bottom is very tricky and will only work for a symmetrical hull. Trying to measure from the top down also won’t work because even hulls with a symmetrical water “footprint” will very frequently have asymmetrical sheer with different heights at the bow and stern. Boats with hulls that are distinctly swedeform or fishform will not sit in the water the way they will sit on a dry, level surface.