Monday, April 27, 2009

Cosine Wherry

Wake Me 2, built and owned by Fred Johnson is made of redwood, Sitka spruce and mahogany. All wood used in the construction of this boat is recycled!

The Cosine Wherry is a strong, lightweight, beautiful, high performance 14 foot rowing boat. It can satisfy the recreational requirements of a family, the practical demands of the sportsman, and the competitive desires of a serious rower. It's light and fast, a joy to row and stable - capable of hauling passengers and gear.

If you want the complete mathematical explanation of how John A. Hartsock came to design the Cosine Wherry, visit

John's comments are those of an engineer, but his closing comment is that of an artist:

"Creating the Cosine Wherry was a rewarding experience. She has given me an appreciation of what must have taken place between builders and users of small boats in the 19th century. They must have been wonderfully intelligent people with an intuitive feel for hull shape and a willingness to communicate with one another."

Thank you Fred, for sharing your beautiful strip planked wherry with us!

Instructions for building the Cosine Wherry can be found in "Rip, Strip & Row!: A Builder's Guide to the Cosine Wherry" by J. D. Brown, J. Hartsock


Anonymous said...

Built mine in the late eighties - absolutely delightful experience - where ever I go, nothing but compliments. Great looking boat, excellent performance, and even went against the Hartsock recommendations and added a small sail. admittedly not the best out there, but it has made going upstream a lot more fun (when wind direction cooperates!). HIGHLY recommend you look at "Rip, Strip & Row" in some depth, before you take the plunge - I got my wood from Flounder Bay, and was extremely pleased with its quality.
DutchProf - IL

Anonymous said...

Built a Cosine Wherry by myself in 16 ft.
length and designed sailing equipment for her (balanced lug 76 sq.ft., daggerboard,rudder). Had some questions about modifications, unfortunately could not get in contact with John Hartsock any more.
Anybody has some ideas ?

doryman said...

What kind of modifications are you thinking of? The sail size you mention sounds about right. John would probably not recommend a sail rig because this boat will sail "on it's rail", but I see no reason for that to hamper a good sailor.

Anonymous said...

As I am more sailing than rowing my wherry,(70/30)I suppose, that increasing the width from 52" maybe to 54 or 55"might result in a more stable boat for sailing,without losing the excellent rowing performance of this wonderful boat?
I am also thinking of lengthening her to 17ft.,to increase stability & speed.

doryman said...

Sounds like you are considering simply scaling the boat up a bit, which shouldn't change it's characteristics, as long as you scale everything proportionately. When a builder lengthens a boat, but doesn't widen it, it's basically another (untried, untested) boat, for instance. I don't have a problem with changing a design, but remember, it's an art and a science and you're often better off looking for a design that suits your purpose.

Anonymous said...

You might be right, scaling up seems to be too complicated. Maybe I should look for another design ( 17 ft Whitehall, 17 ft.Penobscot or 16 ft.Christmas Wherry )I can transport my Cosine Wherry on the roof of the car and would like to do this with the new boat too.
I am still searching ...

pat said...

18If you cant contat John Hartsock, Erica Picket, the owner of Flounder Bay may be able to help. I just contated her for the plans for the modle for /cosine Wherry.
she is on the city council in Anacortes, Ws.
Home phone 360-202-6820

pat said...

anacortis washington

Unknown said...

Sadly, John has passed on.

Used copies of the book exist... Finding one with plans is a bit of a unicorn.

The Anachortes contact number worked in September of 2018. She sold me a set of drawing for 25$

There is also a gentleman in White Salmon Washington that builds these and sells updated (he claims "corrected") plans.

Undersize the rig. Down wind sailing should be ok. Add dagger or leeboards if you want to go upwind... But adding a daggerboard slot will hurt your rowing performance (unless you build a stubby plug dagger for it. Don't expect it to sail like a high performance racing dinghy.

Anonymous said...

I'll gladly upload a photo of my sailing Cosine Wherry if possible.

doryman said...

Sorry anonymous, I don't know of a way to upload to blogger.