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FAQ: Siskiwit LV Sea Kayak

Siskiwit LV sea kayak

The Siskiwit LV sea kayak is an all-around, mid-sized, British-style sea kayak designed to maintain the playfulness of a 16-foot kayak but yield the speed and tracking of an 18-foot sea kayak. The sea kayak plans are designed for wood strip or cedar strip construction. I’ll add questions as I’m asked.

1) Does the rear of the cockpit forms have a smooth transition so that the top of the entire coaming rim is essentially flat? I’m asking because the Siskiwit Bay built with a recess seems to have a sharp transition. I will probably build it without the recess to allow more room for my 5′ -8″ fiance (I am 5′-10″ a 200 lbs. ) If there is a sharp transitions, I don’t mind raising the rear of the cockpit an inch or two and modifying the deck forms.

The drawings come without a callout for the recess. That way you can build as you like or leave it off. I now build them as I did on my Iggy. You can also use Nick Schade’s method, which he writes about in The Strip-Built Sea Kayak: Three Rugged, Beautiful Boats You Can Build. I highly recommend his book if you don’t own a copy. If you leave off the recess the deck flows perfectly without it.

2) I’m trying to decide on the deck type. Although the standard deck allows for more knee room, will it affect the wind resistance more than the elliptical deck? I would like to keep weather cocking down to a minimum.

The deck choice is tough. Think of it as NDK vs. Valley. The standard is sort of like a NDK Explorer and the elliptical is sort of like a Valley Etain. The overall side profile is exactly the same, so the center of effort is the same, which means there’s no performance difference. Just pick the one you like best. For taller people (5’10” and over), go with the standard, because it will fit your height (knees) better.

For weather cocking, add a skeg. It boat is designed to turn slightly into the wind with the skeg up. With the skeg completely down, it turns downwind. Somewhere in the middle counteracts the current wind speed and direction. You can also stop weathercocking by slightly leaning the kayak towards the wind.

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3) I like the look, but I want a shorter kayak. I was thinking in the 16 foot range. Can I change the design?

There’s two ways to go about this. You could scale everything by 94% when you print, and then change the distance between stations by 94% to arrive at a smaller boat that ends up 16 feet long. Or you could just scale the distances between stations. I suggest using the second approach. This will result in a short and slightly more playful kayak while retaining the width, deck height and good looks. Keep in mind that the design displacement goes down by 15 lbs. On a more serious side, your efficiency drops by about 4% at touring speeds.

4) I need an 18-foot kayak for touring. Can I scale this design?

You can. I suggest changing the distance between forms until you get the length you want. Don’t take it longer than 18. For an 18-foot touring specific kayak, I’d actually take some of the rocker out of this design, add a bit more volume for storage and squeak a bit more efficiency at touring speeds out of the hull by increasing the prismatic coefficient. If I get enough requests or someone willing to invest time and money into prototyping an 18-foot Siskiwit Expedition, I could get talked into making a new design.

5) Why 3/16-inch strips instead of 1/4-inch strips? Can I use 1/4-inch strips without changing the plans?

I specify 3/16 inch strip thickness. Most builders will use 1/4-inch-thick strips, but many, including some professional builders are switching to 3/16-inch. On my boats I use 3/16 because it results in a lighter hull, that’s equally as stiff, that flexes slightly more than a 1/4 hull during an impact, and is stronger in tests. From Ted Moores’ Kayak Craft, 3/16-inch cedar strips covered in one layer of 6-ounce glass weigh 8 oz. per square foot, offer 0.73 inches of deflection and fail at 214 pounds. One the other hand, 1/4-inch cedar strips covered in one layer of 6-ounce glass weigh 9.8 oz. per square foot, offer 0.49 inches of deflection and fail at 221 pounds. Add another layer of 6-ounce glass to the 3/16-inch wood and the weight goes up to 10.6 oz. per square foot, deflection becomes 0.9 inches and pounds to failure happens at 500 lbs. On 1/4-inch wood with two layers of 6-ounce glass, the weight becomes 12.3 oz. per square foot, deflection becomes 0.58 inches and failure happens at 450 lbs.

The choice is personal, but during various tests that I’ve seen, 3/16-inch strips with the same layup are equally as strong as 1/4-inch strips. I like to save the weight on the wood, because I don’t believe that one layer of 6-ounce cloth is strong enough on the bottom of the boat. I prefer using either three to four layers of 3-ounce tight weave or one layer of 6-ounce plus one to two layers of 3-ounce tight weave. The lighter weight of the wood helps make up for the extra weight in the glass.

You don’t need to change the plans to use 1/4-inch strips.

6) Do the plans come with instructions?

No, they include only the drawings. I recommend using Nick Schade’s excellent The Strip-Built Sea Kayak: Three Rugged, Beautiful Boats You Can Build as a working manual.

7) What kind of strongback are the plans designed for?

The plans are designed for a simple external strongback. See an example of an external strongback in my Iggy build. I used 2-by-8-inch boards for the iggy. I recommend using 1-by8-inch boards for this one.

8) How do I align the stations onto the strongback? What are the lines on each station?

To align everything on the strongback make sure that the waterline is at an equal height above the strongback at each station. The centerline is aligned and plumb. The different lines are labeled below.

kayak plan station form

To make sure everything aligns correctly, add an equally tall spacer to each station. To make everything the right height make a spacer for your stem stations high enough to raise the stem 3 to 4 inches off of the strongback. Measure the height of the stem’s waterline off of the strongback and make the station spacers an equal height. Click the image below to see a larger example.

kayak strongback setup

9) How are the stems aligned?

The stems mount up against stations number two and fifteen. The lines six inches for the tips of the stems show where station one and sixteen mount. You can safely leave off these stations although using them provides more stability in the cedar strips when you apply them.

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