Improving Jon Boat Stability While In Motion

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kstrayhorn

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Landmark, AR -> Fayetteville, AR
I have done a lot of searching and have mostly found only information about static stability. I am trying to find out about improving the side-to-side stability on my Alumacraft 1232 while moving. Got a motor for it this week, which was advertised as an '87 Evinrude 9.9 but turned out to be an '86 15 with '87 9.9 engine cover cowling. Oviously, that's a lot of motor for that boat. I had water over the gunwale several times while trying it out. The stability seemed to be helped a bit by adjusting the trim, and I feel like it would be even better with at least some weight at the bow. However, I am looking for other ideas to further help as I have fished gear out of the bottom of lakes and rivers before and I would very much like to never have I do so ever again. So this is where I stand with several ideas and more questions.

The first idea I had was some sort of sponsons or outriggers. The system I have imagined up is a pyramid shaped group of 3 5' long 4" PVC sections with some kind of pointed ducting cap on the end for improved hydrodynamics. This would be attached to the boat through oarlock sockets mounted on the outside of the gunwale to make them removable. Obviously one on each side in an outrigger style. However, I don't know if these would work and how well, or how far out to each side I should put them.

I had questions about other possible ideas as well. I have seen hydrofoils and such that claim to help the boat plane faster, which I can plane extremely quickly. But do these have any kind of stability effects as well?
Also, I am strongly considering getting or making a jack plate since I will probably be running the boat pretty shallow on occasion. Considering the physics of these led me to think that having the prop shallower would not push the stern as far in the water when in motion, yielding more boat/water surface contact, and therefore better stability especially off-plane.
Other considerations included a filler extension so I could pilot from the middle bench and have finer control over steering due to leverage, fulcrum length, etc. and obviously stern pods when I can afford them since I really need to build a trailer next.

So what do yall think? Which of these, or any other idea, works best for what I need?
As always, your help is appreciated.
 
Not to be a smart@$$, but I believe it would be much easier to get a bigger boat, gonna be tuff trying to stabilize a 32" wide jon boat.
 
I have considered that option thoroughly and I realize that may be the best in my situation. However, when I bought the boat, I had just tested my old 10' and found that it now leaks badly. I needed a boat in 12 hours, so I just went out and bought this one. Still being under a month old and really only used once, if I could sell the 12' for what I have in it less sales tax, I would in an instant. I just don't know/think that I will be able to without losing my *** on it. But that is still an option, I'm just trying to come up with a plan in case I'm stuck with what I currently have.
 
I realize that. Like I said I bought it on a whim and strictly out of need. I got the 12' because it was the biggest I could get and would still fit in my truck bed. I just posted an ad for it though so we'll see how that goes
 
Used to have a 1230 unknown make/model. All I know is that was 11' 9" long bow to stern, 30" width. Had a 15hp Mercury thunderbolt ignition on it. Stability under way wasn't such a problem as was stability while sitting still, with my brother and myself in it.

Sponsons help but slow you down, and they can adversely affect how the boat turns. Tried that on a 1432. Turn while on plane and the sponsons would "grab" and throw you out of the boat instantly. They weren't homemade sponsons, they were leftovers from when I sold/serviced personal watercraft (jet ski's). I just mounted them on the sides via sealed bolt holes and nuts

Pods won't do much while under way, they just give a bit more flotation at rest for the most part.

Weight distribution will make more difference than anything. Put all the weight in the back, and yes it's going to be unstable-er-more unstable than if the same weights were moved throughout the boat. Wonder if you can move a battery to the front? Or the fuel tank?

Watch the tiller extensions, as you lose steering angle.

Jack plate won't help stability any; but it might help it go faster.

Hydrofoil. I ran one for a while. Had zero affect on top speed, but at part throttle on plane, it was a LOT more stable. Big difference at lower planing speed. When it was full throttle I didn't know it was there. When the motor was buried in water at idle and slow speed (not on plane) I couldn't tell it was there for the most part. It made the most difference when the boat was barely on plane, if I were to let off the throttle just a tiny bit, it'd fall off plane. Probably around 4200-4500 RPM and, somewhere in the 10-12 mph range.
 
Thanks for that input, Todd. Noticed your location, I'm 72206 myself.

I didn't know how well sponsons do in practice and I didn't think pods would be quite what I need since I think I'm looking for more side to side than off the stern. I'll try it out putting more stuff in the front. There's no battery and a 3 gallon gas tank so there's not too much to do there. Might try putting my 285lb fishing buddy or a cooler full of beer on the bow bench.

The thing that's causing me to look for a solution is when I first put the outboard on there. I made a turn not even 90° off plane at what I thought was a low enough speed. The starboard gunwale went under and the only thing that saved me was when I started to fall out with tiller in hand, so it pulled all the way right, bringing the prop out of the water. That's why I was considering lubing the throttle to have better control and a longer tiller so that 1° takes more distance. Radius and arc length and other math stuff. But other than that, it's pretty stable when still. Took it out hunting by paddle in Mayflower with 3 x 150lb guys and our gear and never had a problem, even when each of us stood to take a leak several times.
 

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