Deep Prospector?


I recently got a well-used 17' Prospector, or is it? When I came to measure it, I found out it is no less than 16 1/2" deep, and 35" wide rather than the expected 14 1/2" and 37".

Has anyone ever seen / heard of extra-deep Prospectors? And what about the 35" width? Could it be an extra-extra-deep Cruiser?? I'm confused.

Thanks for any help,

Could it have been narrowed?

If a shorter thwart was used as a replacement it would explain the narrower beam. It would also add something to the depth although I suspect less than the observed 2".
It's a possibility I had not considered. Will look into it on my next trip to the garage. In the meantime here are a couple of pictures.


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I removed all seats and thwarts yesterday, and width increased only to about 36". The thwarts appear to be original and nothing obvious indicates they were shortened. Oh well.

This is a big canoe, and I may end up cutting it down a couple of inches. Needs a fair amount of work too, so I will have time to think about it...


Dave: the construction details are typical Chestnut, but I found no decal under the paint on the deck. And the serial number is 4477 1455 or something close to that. This would more likely be a Peterborough according to Dan's canoe identification page.

Dan: do you mean the ribs in the center section have relaxed and the canoe now has excess rocker ??

By the way, another oddity is the canoe has a rather large and unoriginal looking keel. The screws can be seen in one of the pictures.


Model# 1455 is a Peterborough Canoe Co. Prospector "Portage" with the measurements 18ft x 38in x 15in.

However, model# 1453 is a Peterborough Canoe Co. Prospector "Bush" with the measurements 17ft x 37in x 14 1/2in.
Peterborough's Prospector models could be ordered built extra deep. The question is the width? It is possible that your canoe could have rounded out in the bottom.

Dick Persson
Headwater Wooden Boat Shop
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OK, I checked the serial number again, and it is a 1453. The last 5 was a 3 in disguise.

There is a lines drawing of the 17' Prospector in Roger MacGregor's "When the Chestnut was in flower". I used it to make a cardboard outside template of half the middle cross-section. When tried on the canoe the template touches only at the rail and bottom center.

So, rounded-out bottom it seems to be. Is there a cure for this condition?

Thanks to all,

I assume you know about good Chestnuts and not-so-good ones. About late 60s, production quality slipped. Also I think its confirmed that Chestnut made all wood-canvas Peterboros. So what you may have is a prospector made in New Brunswick from the late 60s on. Certainly the slat seats are dead ringers for Chestnut slat seats.

About 15 inch depth is typical of Prospectors. Unusual depth of yours likely due to rounding out of bottom. Possible that production quality accounts for this. Like it came out of the factory with ribs that weren’t bent enough.

Also you say canoe has a rather large and unoriginal looking keel. It’s conceivable that the keel, if unoriginal and made of stiff wood, could have pulled the bottom of the canoe at the center out of original shape.

I have a 17-foot Prospector from about the late 60s and found several things characteristic of production of about that time.

a. ribs not well secured to inwales. Mine has gaps between the top of the rib ends and the inwales. Yours appears to.

b. check bottom side of thwarts: May not be sanded smooth, but still have saw cut marks. Thwarts may be asymentrical too, like they were cut almost freehand without a template

c. outwale. Earlier prospectors have a nicely shaped outwale: nicely rounded over. (Mine in fact has such an outwale.) Prospector inwales from early 70s have a comparatively crude and unfinished profile, more square than round.

d. last thing to look for is a 45% degree bevel on one (and one only) edge of the ribs. The beveled edge of the ribs will all face toward the narrow end of the canoe. In other words, the direction of the beveled ribs changes at the center point of the canoe. I think the bevel was to ease bending.

My feeling is that if bottom has rounded out some, and canoe otherwise usable and hull symmetrical, I’d go with it as is. An inch and half off ain’t that much, and I see no way to easily bring all those ribs back to shape to spec., unless removal of keel brings it back to 15 inches.
Also I think its confirmed that Chestnut made all wood-canvas Peterboros.

I believe it is true the commercial canoes (Prospector, Cruiser, Freighter, etc.) were all made in the Chestnut plant, but all three companies made canvas covered pleasure canoes. My own Peterborough Minetta was made in the Canadian Canoe Co. factory in 1961.

I would agree with most of the points Larry makes about the declining quality of construction in the late 60's and 70's. My 16' Prospector shipped in January 1979, and was shipped with ribs broken during construction. However, my ribs are not bevelled as described - instead, they were rounded over, then the taper cut into them, leaving a square edge along the tapered portion of the rib.

If the bottom has indeed rounded out, it will have an impact on both primary stability and tracking - the boat will feel tippier, especially when paddling light (this will diminish the heavier you load the canoe) and the rocker has also been increased quite a bit. It is possible to re-shape a rounded hull, though it is going to be much easier to work with a canoe that was meant to have a flat bottom to begin with. You'll need a strongback shaped to the target rocker curvature, a means to draw the gunwales and strongback together, a good soaking or steaming, and patience. Whether it is worth it to try this may depend on how badly you want a 17' Prospector...
Deep Prospector

One thing I’ve learned over the years is not to take anything for granted when it comes to the three big Canadian canoe builders, i.e. Peterborough Canoe Co, Canadian Canoe Co and Chestnut Canoe Co.

I’ve had many “Prospectors” come through my shop for repairs and restorations. Have they been generally consistent in quality and construction details? The answer is a definite No!

Good examples of discrepancies are the ribs;
size, shape and spacing vary quite a bit as does the quality specifically from the late 1950’s.

3/8” thick x 2 3/8” wide spaced 2” apart,
3/8” thick x 2” wide spaced 2” apart,
5/16” thick x 2” wide spaced 1 ¼” apart,
5/16” thick x 2” wide spaced 2” apart,
5/16” thick x 1 ½” wide spaced 2” apart (no tapering in width),

Looking at the various given “Prospector” rib dimensions in the catalogues from the three companies; it seems that Chestnut Canoe Co was consistent through the years with a rib 3/8” x 2 3/8”spaced 2”apart.

Canadian Canoe Co seems also to have been consistent through the years with a rib of either 3/8”x 2” as well as 3/8”x 2 3/8” spaced 1 ¼” apart.

Peterborough Canoe Co is sort of consistent up to the early 1950’s. After that and specifically between 1956 and their closing in 1961 you will in reality find all of the above five listed rib dimensions in Peterborough “Prospector” canoes.

So, who built those “Prospectors”? :confused: I don’t think we ever will be absolutely sure, case in point; when carefully looking through their catalogues you will also find canoes (both Prospectors as other models) with Chestnut decals in Peterborough catalogues and vice versa.

Dick Persson
Headwater Wooden Boat Shop
I went out to measure my 17-foot Chestnut prospector and I get 15 and a half deep. Width depends a lot upon where you measure. I get 32 or 35 and half inches wide. 32 is from inside of the inwale to inside of the inwale along the center thwart. 35 and half is from outside of outwale to outside of outwale. Hull has some tumblehome so widest point of hull width may be in excess of 36. But I would say your 35-inch width is pretty much on the money for a Chestnut prospector.

Everything in the photos looks late Chestnut to me: slat seats, thwart shape, deck cut out, and rib ends not well nailed to inwales. A profile pic would help. Overall should look slab sided, not much rise from center to tip. Look for a couple of conspicuous extra wide planks about at the sheer along the middle. This also seems characteristic of Prospectors.

Identity seems the key. Is it a Peterborough with dimensions expected of 1453 or possibly from a murky time in the 70s when Chestnut was making prospectors for Peterborough and not picky about hitting the Peterborough advertised dimensions? Depth is not that far off and width pretty much on the money.
The Prospector could be ordered extra deep from Chestnut, Peterborough as well as from Canadian. So it is entirely possible the Prospector in question is one of those so ordered.

When measuring a canoe for catalogue purposes, most companies measured as follows:
Width; measure from outside to outside of canvas at the widest point quite often 5 to 6 inches below the gunnels. (Do not measure the width over the gunwales)
Depth; measure at the canoes centre from the top of the gunnels to the canvas outside.

As this canoe has a Peterborough Model/serial number and slat-seats it was likely built sometime between mid 1950’s and 1961 when Peterborough Canoe Co closed down.
(Of the three companies only Chestnut survived to finally close in 1978)

It would be interesting to know how wide the ribs are, as well as the the rib spacing.

Dick Persson
Headwater Wooden Boat Shop
Yeah I would say amen to Dick’s and the gist is that what you’ve got is not that far off paar for the course. Peternut or Chestboro and don’t get too bothered by an inch or two here and there.

I looked agin at mine and note I exaggerated the bevel, more like 60 degrees and the opposite edge is tapered, but not the beveled edge. All I’m suggesting is that these seem to be traits of late 60s Chestnut prospectors. My authority is having one of my own, having a few others say these traits are on theirs, and the word of a one-time American Chestnut wholesaler, now deceased, who was my authority. So it may be an intentionally built deeper Peterborough, or a Chestnut a bit off kilter.
On this particular Prospector:

- the ribs are 2-3/8" wide. The spacing varies, but I guess you could call it 2" on average. Each rib has one edge bevelled, the other rounded over, as Larry described.

- it looks as if each rib end was fastened to the inwale with only one nail.

- planking is 3" wide. It goes like this from bottom to inwale: 5 planks, 2 gores, a very wide plank (5" maybe) and a sheer plank.

- the rounding over of the thwarts is not symmetrical top-to-bottom, as if they used a 5/8" bit on 3/4" stock, maybe to give an illusion of lightness. But left the lower edge square. And yes, there are saw marks underneath!

- outwales (what's left of them) are well-rounded, inwales squarish with edges relieved.

Just to clarify: the 35" width was inside the planking at the widest point. I later measured 35-3/8" to the outside of the planking (canvas is gone). 16-1/2" depth was from top of rails to bottom planking inside.

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I was going to mention the possibility of one nail per rib, likely not even a ringed boat nail, but plain steel.

And the big 5-inch plank is there.

Unless Peterborough quality slid that much that early, I’d say late 60s Chestnut prospector.

How are the planks? Likely flat sawn, rather than quarter-sawn wood.

That’s what I started with and I love the canoe.

I don’t know about the 16 and half-inch depth, whether that’s distortion or just as extra deep prospector.
Yes, planking is mostly flat-sawn. For some reason, it seems they used the longer planks towards the ends and filled the middle section with shorter pieces, so there are many joints in the middle.

I'm still puzzled with the depth. I checked again and it's 16-1/4 to 16-1/2 at all 3 thwarts.

I'm not quite sure how rocker is measured, but a taut string held 1-3/4" off the hull about 2 feet from the ends clears the bottom with room to spare.


There is some good information about rocker at on the Old Town Canoe site. A canoe with no rocker will have a straight keel. A canoe with rocker will have the middle of the keel lower than the ends. A 'hogged' canoe will have the middle of the keel higher than the ends and this is usually not considered a design feature.


As your canoe has a Peterborough serial/model number it is quite likely that your canoe was built no later than 1961. Also, from your posted measurements and description of construction details it is likely that your canoe was not built before 1956.

As for the discrepancy in depth and width; I think it is possible that the rounding out of the bottom is the culprit. It is also possible that the canoe could have been ordered extra deep.

See attached sketch of a canoe section: black line rounded out bottom and red line original hull line. Note that thwarts stay the same width.

Dick Persson
Headwater Wooden Boat Shop


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