> As indicated in my previous post, I have a new boat which is
> very nice in all respects except that it has a prediliction for going
> to the left when I want it to go straight.

My canoe does that when I paddle on the right side and don't J stroke. Is it possible you are stronger on the right side of your anatomy and putting more ooomph into strokes on the right side? If so, do some weight training emphasizing building up your left side or see a trainer. While this sounds strange, every one is familiar with being either ``right-handed'' or ''left-handed''. There are also some people show this to excess, and have one side of their body much stronger than the other.

Going back to much older wooden boats, In the book Ben-Hur, Lew Wallace has the title character, as a galley slave, asking to be changed from an oar on one side of the galley to an oar on the other side, so he could develop his muscles evenly.

> I believe, but am not sure,
> that this is due to a slight curvature in last 18 inches or so of
> keel.

This is probably more likely than you having a lopsided anatomy and not knowing it. Does your boat have an actual external keel, or are we just talking about the center seam on the hull? If it is a real keel, or a skeg, cut the thing off, ( or at least the last 18 inches) sand things smooth, and patch with a fresh layer of fiberglass.

If there is no keel to remove then the thing to do is to find out if the hull is twisted before trying any ''cures''. Flip the boat over, stand at the bow and sight along the center seam. If the bow and stern run in a straight line all along the length, then there is no problem here. If the stern runs off to one side, then get a friend to stand at the stern with pencil. Play surveyor. Stand at the bow, sighting along the center, and have your friend move the pencil near the stern, left or right, until it appears to be in line with the axis of the boat. When they touch the point to the hull it may appear to be 1/4 inch or more away from the center seam. If so, then you have found your problem. Now have them move the pencil forward a foot or 18 inches from the stern. Repeat the process, moving forward a foot or so until the pencil mark lands on the center seam. Using a straight edge, connect the pencil marks and you'll get a pretty clear picture of how much the center line has shifted, and where the shift started.

Let's suppose the pencil mark by the stern is 1/4 inch from the center seam. This would indicate a twist that moved the centerline 1/4 inch off center. If the wood was thick enough, I'd take a plane to it and remove the high material, reshaping the center line. If you are dealing with strips or plywood, that is probably not an option.

Another option is to build up the hull with thin strips, rebuilding the center line where it belongs. If the shape shifts over only 18 inches, this adds a small ( practically negligible) amount of weight to the hull maybe 6 ounces. If the centerline shift was 1/4 inch, I`d add a wedge shaped piece that was at least twice that distance in thickness, an tapered to a point over the length of the shift. In this proposed case, the wedge would be 1/2 inch thick and 18 inches long. The width of this wedge is a variable. I'd scribe the hull on the high side, make a template, and try to match that on the low side, making my wedge as wide as necessary. It could be faster to put on a wider, longer or thicker piece of wood than called for, and work it down with a plane or belt sander with a very coarse grit belt.

the idea here is that it the twist is 1/4 inch to the left, by adding 1/2 inch of wood, you are building in a twist of 1/4 to the right. The end result is a slight flaring of the hull at the stern. While I would not want this on a race boat, this is not going to noticeably slow you down. By the time you sand the added piece so that it blends into the hull, and cover it with fresh fiberglass, resin and varnish, it will be totally unnoticeable. The only way someone could find your fix is if they were to measure the thickness of the hull at that point.

If you want to, instead of using a large single wedge, you could build up the material from strips of wood or plywood.

> I have considered a number of options and would appreciate any
> input as to the merits or lunacy of any of these ideas.....or other
> thoughts or considerations.

> Option 1 - live with it and paddle harder or with more sweep
> on one side. I really don’t like this one.

You could also build a paddle with a larger area on one side.

> Option 2 - Install a rudder. If I really have to but I am one
> of those types that is strongly predisposed to not having a rudder.
> I don’t like the mechanical metal and wire moving part clutter of
> rudders.

A rudder is a good option.

> Option 3 - a fixed rudder or fin that I would never have to think
> about after I put in on. I kind of like this. On Sunday, I attached
> to hull near stern, on one side, a piece of foam cut out into a wedge
> shape. I also took several pieces of 15 or so inch rope and taped
> them to bottom of hull at an angle such that they would hopefully
> tend to steer boat to right to compensate for the other leftwards
> tendency). This combination seemed to pretty much correct the problem
> (can’t say yet how much either the wedge or the rope ridges contributed).
> What I see as an advantage to the wedge on side of hull, as opposed
> to a fin, is that it would never be in a position to get snapped off.
> If I go with this option, I would make a wooden wedge, kind of like
> a door jam and attach it near stern.

If you read above you'll see that I use the wedge idea right along the centerline of the hull, and blend it into the hull shape. I don't think you want a lump somewhere else along the hull. It would really look unusual.

> In thinking about all this, there are a number of things that
> I realize I don’t know about but would like to know about. First,
> is there any reason why rudders . . .

I'll defer answering rudder questions. a book on sail boats might have more pertinent info. Maybe a rudder expert can fill us in.

> Option Last - radical surgery. Cut away the offending last 18
> inches of boat and have a kayak with a transom. Does this markedly
> increase drag or have any other untoward effects? I wish I had one
> of those naval architecture computer programs. Obviously, this is
> a major and irreversible step but its a possibility.

Lop off the last 6 inches to make a square ended boat and you sacrifice little. Lop off the last 18 inches and you lose balance and a mesureable amount of bouyancy. Your maximum capacity is diminished by the lost displacement and you will have to move your seat and perhaps the cockpit forward to balance the boat. Either that or lots of weight in the bow for ballast. This is not a good idea.

Of course there is always the Rambo approach. Use violence, and if that doesn`t work, use more violence. If you are thinking of radical surgery, I'll give you two scenarios: Lets assume that when the boat is upright the tail shifts to the left a bit.

A:) Grab a saw and on the right side of the boat cut from the center line of the deck through the side, down to the centerline of the hull. Put pressure on the hull to cause the kerf to close. This bends the hull back in the direction you want, and you can glass over the area to holdit in the new shape. You may need several slits or a wide slit to get the proper bend.

B:) The other option is equally radical. Same kind of slit, from center of deck to center of hull, but on the other side. Now, insert Wide, thin, wedges in this slit to cause the back of the boat to bend back to where it ought to be. When the amount of bending gives the desired result,(thins are straight) fill the gap with thin strips of wood ( probably the size of matchsticks), pull the wedges, and cover over with fiberglass and resin. This will probably make that part of the hull significantly weaker, so you might want to beef up things on the inside with a backing strip, or several extra layers of fiberglass. The cut will look weird when it is finished. C'est la vie.

Hope this gives you some ideas.

Paul Jacobson