Maybe we worry too much these days. I was brought up with single channel R/C. To get right rudder, you had to go full left first. ( could be full right then full left depending on tiller fitting)
Now that did upset a boats dignity!

On R/C model power boats 🚤 all my friends and me have added a small wedge on the bottom of the hull at the rear edge. This has compensated for the roll. Also we have cut off the leading edge of the rudder up to the rudder post and this has stopped the bow from digging in on the turns. On several model power boats I have seen turn fins, I presume these may be used in the same way as you describe the bilge keel is for. But this I am not sure about this as I have never had one of them fitted🤔.

Hi Jim,
See my reply to Rick (Newby7).
Apropos torque roll,
yes you are right, especially with single shaft boats and ships.
Caused by the upward thrust of water from the prop against the hull being on one side only.
In particular with low speed high torque vessels such as tugs and smaller freighters.
Some skilful Captains use this effect to shove the stern of the ship to the quay when docking🙄
This is also the reason why twin shaft vessels have the shafts / props rotating in opposite directions to cancel out this effect.
I assume that your fishing boat has only a single shaft so ballast, deeper keel, bilge keels are probably your only options.
I'm wondering if I'll have the same problem with my Gina 2 Danish fishing boat when the restoration is finally completed🤔
Cheers, Doug 😎

Bon chance mon ami👍
Let us know how it goes.
Cheers, Doug 😎

Thanks Doug for the post this will help me do the bilge keel.
Rick

Hi Rick,
As the name 'Bilge' keel implies they should be fitted along or just under the bilge, lower part of the hull.
Fitting at the waterline will have little or no effect as they are intended to work together.
If the roll is far enough to lift one out of the water the effect will thus be diminished.
'Waterline' can also vary according to the load!
Naval ships that I have been involved with (patrol boats up to LPDs and light aircraft carriers) all have bilge keels approx 1/3 to half the hull length fitted amidships, just below the round bilge angled out at ~40° to the horizontal.
On small fishing boats / patrol boats I have seen them fitted under the bilge almost vertically, thus also giving support to stop 'em falling over when beached at low tide😉
Same applies to hard chine hulls, fit below the chine line at the mid section.
Hope this helps, cheers, Doug 😎

Hi Collin That helps. Will look up on google to get more information.
Rick

Good evening Rick,
I've been thinking about this as I have a blow moulded hull that I will be trying to do a model of one of my dads old fishing boats.
I remember helping him one winter back in the 80's fit a pair to his boat as the harbour used to dry at low tide and he wanted them to help protect the hull.
We used 8x3 inch oak and bolted through the hull with inner braces to the inside frames.
Then coated and shaped the outside with fibre glass followed by a strip of 3"x 1/2" stainless Steel to protect them from the stones on the harbour bed.
I googled bilge keels images and it shows loads of styles on there, the idea is for them to act as a sideways drag to stop roll and they work well on real boats.
You will need to look at what style suits your hull shape.
Cheers Colin.

Hi Collin I have a billings fishing boat (Progress) I will be reworking soon.It was my first boat kit.The subject of boat roll I went back and read the posts again as this boat tipped on me.My question? Would bilge keels help and are they at water line or just below .The other is how long and wide would they be.
Rick

Like your thinking, but unless you are changing speed suddenly, plus this would normally be associated with an oversize motor in a boat.
Even that could be reduced by the addition of bilge keels.
Cheers Colin.

Hi chaps , been thinking a bit more about the boat roll. I wonder if its the torque being produced by the propellor. you get tremendous body roll on some of the more powerful cars. l have quite a few spare 2/3 bladed props l think try a smaller size and see how it go,s
But that will be when when they open up the club pond.
stay safe.

I agree with Colin that a pair of bilge keels could considerably help with your rolling problem. I note that you have already tried ballasting, but have you put in enough. It is surprising how much you need sometimes

Nerys

Rick roll is usually caused by instability or too high a centre of gravity.
Under what conditions is it most noticeable,
Sometimes wind on the superstructure can cause an imbalance.
Cheers Colin.

Can an out of balance or bent prop have influence on roll.
Just thinking outside the box I have no knowledge of this.
Rick

Can you put some photos, showing hull shape, it may need a pair of bilge keels. I suggest this as it was a problem on a full size boat my family once owned which we cured by fitting a pair of bilge keels.
Cheers Colin.