C-Forum

During my initial test run of my new Mamba it would spin out sometimes after getting up to speed (flat water/fast current). Once it started to "grab" correction strokes wouldn't do much to straighten it back out and I would end up backwards. Will being too stern heavy cause this?

I knew I was stern heavy on the trim but couldn't move forward b/c the thigh hook/backband mounts were still there (not for long though). Also mind you it was an initial test run (no outfitting, just a ghetto temporary saddle)

I've had that problem when boats were bow heavy, because the stern tries to come around the bow.

First, get help from a second observer on the trim. Second, if it is not out of trim, experiment with edging the boat a little, and make sure your stroke is well forward so that you are pulling the boat forward at its nose.

I agree with ezwater....when my boats are BOW heavy, they swap ends and I end up backstroking a lot....quite successfully, I might add. So I add gear behind me (in a Caption), and move the center of mass toward the rear.

When the boat is stern heavy, it acts more like an arrow in flight. Bow heavy, and it acts like an arrow flying backwards.

Thanks, that definitely makes sense.
I was paddling with someone else, he said the stern looked quite a bit lower, which is why I just figured it was b/c I was stern heavy. I think I'll have to have someone take pics so I can see for myself.
I learned real quick to paddle from the bow, when trying to do full strokes past the hip....not so smooth. The boat surprised me how well it tracked and would get up to speed, that is until I would spin out.

I'll have to respectfully disagree here. I've converted numerous creek boats of similar design including the nomad, and this issue almost always occurs when the saddle is not far enough forward.
It's an interesting phenomenon and a little bit paradoxical. Don't spend too much time rationalizing why it works this way, because there are a lot of factors involved. I've wasted a lot of brain power on this and ultimately trusted the direct experience of doing this over and over.
For a Mamba, I would suggest starting with the backrest at least 10 inches forward of the rear cockpit rim, and maybe 12 might be better. You're going to need a custom skirt for this. Remember these converted kayaks are designed with the intent of having your legs and a bulkhead up in the front of the boat. When none of that is up front, and the c-1 saddle is too far back, the stern is much lower in the water and tends to be much more at the mercy of the current. This will be even more true in the Mamba, as the stern is not quite full volume as compared to other creek boats. The bow on the other hand is huge, and you can stuff all kinds of weight up front. When I do overnight trips, almost all of my gear goes up front, and the boat remains easy to control. Try this experiment: Take a 10-15 lb weight, and put it all the way in the stern and paddle your boat. See if this exagerates the problem. Now take the weight and put it all the way in the bow, and I bet it will feel better.
If you go too far forward with the saddle, you will notice that you lose control in rapids and have a less effective rudder stroke for some reason.
The other weird thing, these short creek boats actually boof better when the saddle is farther forward. I think this has something to do with the leverage and timing of the stroke in relation to the center of gravity, and the fact there is less of a moment arm to fall down away from you before the center of gravity reaches the lip of the drop. This can be a good thing on really tall drops where you don't want to boof, but for 99% of creekboating you want the good boof.

Wow, sounds like I have alot more experimenting to do to see what the issue is.
Thanks

We may have the affects of sinking the stern below the water level, or catching it's stern "edge" here being more critical to the discussion than that covered in my initial reply. The effects of the water pushing the boat around with the stern too low and the water water catching the edges and coming over the stern deck may be the cause of the lack of directional stability.

In my Caption, I only have to deal with what part of the boat contacts the water "from above." If I've sunk the stern to catch the stern edge of the Caption (below water level), I've got other problems going on besides directional stability... Sounds like JFD's experience may be much more applicable to your problem, than my experience with the open boat is.

My daughter has a new (to her) C-1 Slalom boat. It's overall too big for her weight, and as outfitted, she sits VERY SLIGHTLY stern low. Directional stability is fine. She doesn't have quite enough weight to sink the stern more than an inch for a pivot turn. We'll go play around with some weights to exagerate stern and bow low on her boat, and see what happens to her directional stability.

???

My suggestion that the paddler's weight might need to be farther back is based on personal experience with three c-1s: my old Phoenix Seewun/Slipper that I paddled for many years, my Dagger Zealot, and my Millbrook Wide Ride. In the case of the Phoenix, it was never a great boat, but it worked better when I was lighter. As my weight climbed over the years, the tendency of that very Swedeform boat to sink in at the bow and wag at the stern became more pronounced.

The Zealot was a boat accused by others of having to be paddled cab-forward, and being catchy at the stern. I weighed about 205 in the years ('96- '04) when I was paddling the Zealot a lot, and I never found the stern catchy. Instead I found I had to make very deliberate effort to submerge the stern. While the boat was happy to be paddled cab-forward, it also behaved quite nicely for me sitting up. I think the critical difference between my experience and that of lighter, shorter Zealot paddlers was that my long, heavier legs and my long torso biased the weight forward.

I bought my Millbrook Wide Ride used, to get a boat more comfortable for my knees than the Zealot. I soon found that, at my weight and height, the boat did not behave properly unless I sat up straight to unload the bow. I think that if I were a shorter, lighter paddler, I could paddle leaning forward as if I were in my Zealot. But the Wide Ride is somewhat Swedeform, and if the boat is trimmed too much toward the bow, it tends to roll and fish around on the bow, and the chines toward the stern do not engage.

So I suggest, if you are a smaller, lighter paddler, and your c-1 is misbehaving, FIRST consider whether you need to shift your weight farther forward.

But if you are a larger, heavier paddler and your boat misbehaves, see if there is a way to shift your weight bias toward the stern. Unfortunately, that may require cockpit rim modifications. I don't think either my old Phoenix or my Wide Ride can be made "right" for me unless I find a way to move the cockpit rim, and my butt, sternward.