Modifications for stability in rough water

[Brian-Up-North]

Are there any modifications we can make to make our macgreggor power sailors to make them more stable in rough water?

I realise to have the option of speed that we have planing hulls where most dedicated sailboats have displacement hulls and displacement hulls are more stable (but so much slower!).

I also realise that water ballast does not put the ballast in a weighted keel which would increase stability. I appreciate that water ballast allows a low towing weight, but I would like more stability if possible

I would be most thankful for any potential modifications

[Gazmn]

Make sure your water ballast is completely full. Partial full can be dangerous & complicate stability & safety. I keep my house batteries low & close to centerline. Same with Engel refrigerator & cooler. Any heavy items keep low & secure. After that Avoid heavy weather & stay safe

[Wayne nicol]

like the fishing boats that use para vanes, i wonder if there would be any benefit to dropping a line overboard, either side, about midships, with two small paravanes on them.
that may dampen the roll.
is this for at anchor, or for underway at low speeds?

it could be improved upon, by having two short spars, stayed out from the gunnel, back to the mast step- kinda where the baby stays are- then have two small paravanes on them, further outboard they are the more pronounced the effect.
one would obviously have to de rig when sailing.
the little gin poles could have an enclosed block at the top end- so that the paravanes could be retrieved or deployed easily- without smashing against the hull of the boat.

[Jimmyt]

Brian,

In addition to Wayne's request to identify how the boat is being used when you experience poor stability, please explain the sea state that you are interested in and angle of attack, i.e. following, quartering, reaching, beating, or motoring flat out dead upwind...

I've been out in some reasonably bad stuff and never thought the boat was unstable. Curious to get more specifics regarding the conditions and what you considered indications that the boat was unstable.

Thanks,
Jim

[sailboatmike]

Much Like Jimmy, I find my X revels in rough conditions, you can get a nasty roll and yaw when the seas are coming from the rear quarter though, I counter this by raising some sail to counter it, for a while I always wondered why I would see boats coming the channel into my old home port with their jib up, then it dawned on me when the sea state came up and I was taking nasty wave from the port rear quarter when coming in, the boat was rolling and yawing like a bucking bronco (very nasty), then I thought lets raise the jib a bit like I have seen on other boats coming in , and low and behold the boat motion became very stable again.

It works like this, the wave hits you in the rear quarter pushing the stern one way so the bow get pushed the other as the swell goes under the boat, the stern lifts and the bow falls off the swell, with the jib, it stops the bow being pushed around anywhere near as much. I also try and keep between swells by adjusting the motor speed coming up the channel, that big motor come in handy at times

[whgoffrn]

You'll have more stability with all boards down and as much sail up as will get a heel of 15-20 ... if you can get the water ballast to work for you as well as the wind pushing against the sail .... if it's from quarter following seas a drogue works great at keeping the stern planted

[Wayne nicol]

i do agree with Brian though, in big consistant waves the macs are pretty good, in small chop they are good, but in a sloppy, bigger sea, usually when i find the wind and tide are opposing, i find my can be a tad "rolly".
i can only think its a combination of high windage, a long moment arm of the bare mast , and the lack of chines, that even with the ballast in, at low speeds, it can give the impression of being unstable.
although i have the utmost faith in the boat, as we have had her out in some pretty big conditions up here in the Far- Pacific North west.
maybe next time i will try a bit of centerboard down at the lower speeds.

this is all while motoring of course. Under canvas she stiffens right up.

[BOAT]

Rolly Polley does not happen on 'boat' under power at planing speed - when I am going that fast the boat is slamming into the waves, not rolling around. I run those conditions with the ballast empty if I am going to slam the waves.

If your talking about under power at displacement speeds it's not any more rolley polley than any other mono hull if you just fill up the ballast tank - the deal with the M boat is just that your sitting up so high in the air - the cockpit seat is over 4 feet above the water!



I was out on a friends 55 foot fishing boat up in the wheelhouse and when that thing rolled back and forth it literally threw you from one side to the other. It has a lot to do with how high you are off the water.

The next time you boat is rolley polley in the water just step down into the cabin and stand on the floor there - you will see what a huge difference it is when you get down lower in the boat.

ALL boats are that way - it's no big deal. If the rolley polley really bugs you when underway under power at slow displacement speeds just raise the main sail and that will help.

[DaveC426913]

If the rolley polley really bugs you when underway under power at slow displacement speeds just raise the main sail and that will help.

Doh!!

Gonna hafta remember that one.

[DaveC426913]

That reminds me.

My boat is Sea Saw, for obvious reasons.

Yesterday, I encountered another boat (not a Mac) called Zig Zag.

I immediately thought: "Now if I find a boat called Roly Poly, we've have a full set of rotations! Pitch, Yaw and Roll."

Any pilots out there?

[Brian-Up-North]

Thanks for all the input and questions.

I was out in rough weather in my X using the outboard (not sailing) with the wind and large waves hitting me from behind at angle just off the stern. Each wave momentarily increased the speed by 5 knots, but made steering very difficult as the waves turned the boat almost 90 degrees with each wave.

I am curious for any tips others have on using their macs in rough weather

[sailboatmike]

Thanks for all the input and questions.

I was out in rough weather in my X using the outboard (not sailing) with the wind and large waves hitting me from behind at angle just off the stern. Each wave momentarily increased the speed by 5 knots, but made steering very difficult as the waves turned the boat almost 90 degrees with each wave.

I am curious for any tips others have on using their macs in rough weather

Pull some jib out and you will be amazed at the difference

[Jimmyt]

http://www.wavetrain.net/techniques-a-t ... ling-waves

As Mike says, sail will help. Interesting article which you may find helpful as well. They have a couple of diagrams that help explain the technical jargon...

[whgoffrn]

My vote is for drogue with what u just said ... but u obviously cant motor fast with one and I doubt I'd try any faster than 5 or 6 kts..... u can try rolling out a patch of jib and sailing but the conditions you described are the conditions that cause the most stress on the rudders and brackets ...so sailing on jib alone most likely would be the way to go but the scenario you described is what has broken a couple macgregor rudders and or bracket. If its just a short trip back to calmer seas I'm sure it would be ok but if you think its going to be a couple hours of sustained abuse to the rudders and or brackets I'd be chucking the drogue over

[DaveC426913]

I was out in rough weather in my X using the outboard (not sailing) with the wind and large waves hitting me from behind at angle just off the stern. Each wave momentarily increased the speed by 5 knots, but made steering very difficult as the waves turned the boat almost 90 degrees with each wave.
I am curious for any tips others have on using their macs in rough weather

Increase your speed to something closer to the wave speed. You should be able to find a happy speed where the rolling, yawing and pitching is dramatically reduced.