Another Blue Hole question

I just bought an old Blue Hole OCA Prowler. Somewhere in its’ life it took a big hit on the bow. Looks like past attempts to remove a big dent resulted in several smaller dents. I could fix this by doing a bit of filling and grinding and then hiding the whole mess under a skid plate. Or… if this is a symetrical boat, as it looks to be, I could swap the seats and turn around the portage yoke and, presto! a new bow to bang up.

Does anyone know if this boat is, indeed symetrical?



Isn’t it an OCV Prowler?
The OCV Prowler was symmetrical. Sort of like a flat-bottomed OCA.

You can reverse it. But unless the
warped bow extends below the water line, you don’t need to worry about it.

And if you do try a cosmetic repair, don’t cap it off with a Kevlar felt skid plate unless you just like the looks. Kevlar felt is a poor repair material.

Don’t honestly know. The boat was advertised as an OCA Prowler. It says Prowler on the sides and has Blue Hole decals bow and stern. The hull no. TBH19130I989

A little research
suggests that this boat is an OCV. It does have a flat bottom and vinyl gunwales.

The damage is about at the water line. Currently the area is sound enough, but it may not take many more hits. I’m leaning towards swapping the ends. This was a cheap boat and it will be used when I don’t want to bang up my better boats.

The Prowler is just the OCA hull trimmmed with vinyl gunwales. Thats why the OCV model number.

Same mold?
So the OCA and the Prowler was formed on the same mold?

I thought the OCA had somewhat more arch in the hull bottom, although perhaps the different gunwales and maybe different thwart lengths effected the hull shape.

I must admit, I never compared them side by side.

Look, measure. Does it matter.
Peter, I don’t know for sure if the OCA is symmetrical, though I always thought of it as being so.

The three areas that are important re symmetry or asymmetry are:

  1. The waterline. The “footprint” of the hull on the water’s surface. A symmetrical waterline will be widest in the exact middle, and taper identically toward each end.

  2. The rockerline. A boat with symmetrical rocker, when set on a flat floor, will have both halves of the canoe sweeping up off the floor to their respective ends in the same curve.

  3. The sheerline. A boat with a symmetrical sheerline will have gunwales that sweep up from the middle to each end in the same curve and to the same height.

    Put the canoe on a flat floor and look at the rockerline and sheerline. Measure them if you want. You can judge the waterline by just looking at the bottom of the hull or by tracing around it with chalk.

    You can probably come to some pretty close conclusions about all three lines simply by your own observations and measurements.

    Then, even if there are some asymmetries, ask yourself how much this matters. That is, if you are going to use this for goofing around in modest WW, which I assume, some slight asymmetry in any of these lines may not matter in any practical sense. There are symmetrical WW canoes and asymmetrical WW canoes.

    The one asymmetry that may matter some is sheerline asymmetry. Usually, if there’s a difference in height, the bow will be higher than the stern in both WW and FW boats. Even there, however, an inch isn’t going to really matter for a knockaround play boat. If you get WW serious, the OC? will get jilted anyway.

    Alternatively, paddle it backwards until you crash into a sharp rock. Then you will have symmetrical dents.

I’ve noticed that some are very
concerned about asymmetry if they have to paddle a boat in whitewater. Yet now it’s difficult to buy a true whitewater open boat that isn’t markedly asymmetrical.

Before outfitting such a boat, new owners should have some fun and set the boat up temporarily so they can try paddling it in either direction. It may surprise them that it will be “different” but that neither direction feels unworkably wrong.

When I bought a Mad River Synergy about a dozen years ago, I noticed that it was markedly Swedeform (notwithstanding Mad River’s stupid statement that it was fishform). Many older whitewater OC-1s are Swedeform, but starting in the 90s, Kaz of Millbrook and others started making and racing fishform boats.

I decided to compare fishform and Swedeform by trying my Synergy in both directions. It was just about the way one would have predicted. Running fishform in reverse, the broad upturned bow could ride easily over stuff, and could be horsed into new directions easily. The narrower “stern” trailed along and aided tracking when I sat vertically.

In swedeform mode, the Synergy had a much more traditional feel. If I leaned forward to paddle hard, the narrower bow tracked well. To turn, I had to sit up, or even back, to get the bow loose and pivot on the stern.

I could have outfitted the boat either way and have been happy with it. The Synergy is a bit of a “wet” boat in swedeform mode, but would be a drier boat in heavy whitewater in fishform. But in fishform mode, it is slower. In it’s design swedeform mode, it is fast for a whitewater canoe, and a good river cruiser.

What I am suggesting is that the synergy issue may be over-rated. Lots of whitewater boats may perform well in forward or reverse, and one needn’t hesitate to change a boat into reverse just because the bow is crumpled.

Trial to come
Thanks for all the advice. I had never really thought deeply about the implications of turning around an assymetrical boat, but as I read it all makes sense.

As things turned out, I’m going to take the boat on trip with low water starting tomorrow. I have not yet made any modifications and will be running it “backwards” as that is currently the best solo option. By the time I get back I should pretty much know if I want to “turn the boat around”.

Or, as Glenn has suggested, I may have crashed it and have dents in both ends.



Dagger Prophet
The Prophet is radically asymmetrical with an enormous amount of rocker on both ends, but greater in the nominal “bow”.

A couple of years ago I reoutfitted mine to paddle “backwards” so it is now “kicked up” in the stern like a Mad River Howler.

It works quite well and still has more than enough rocker in the bow to stay dry.