Some physics based and hypothetical questions

[jjan]

Hi,
This question is mainly aimed at engineers and those with a good knowledge of physics and design but anyone else with experience in this situation please chip in. I am waiting delivery of My Macgregor from the factory in 3 weeks, but despite years of reading the great points about this boat, I still have this niggling thought at the back of my mind that won't go away about unballasted stability after reading some of the forums. Just when I thought I have read and seen enough to feel really confident, I will find some adverse comment regarding stability issues. When I look at the Macgregor factory video, I see Roger Macgregor happily pulling on one of the mast stays and leaning backwards over the side of the ballasted boat saying something about it not tipping with his 180 LBS weight. Hypothetically, what would happen if the boat was not ballasted? Also, I know that roger says in his video that it takes 130LBS at the top of the mast to hold a ballasted boat down but what kind of force would be required to pull over the boat at cabin level or 6ft above cabin level?. Will my 350LBS outboard also add extra stability to the dry boat?

I am talking about calm waters with no sails up, not rough or choppy seas with gale force winds. I realize that in an ideal world we would all follow to the letter the warnings on the boat but I know that there are many on this forum who sometimes do go unballasted and climb across the cabin for whatever reason. I do not intend to fix a large ferris wheel mod with seating for 30 to the top of the mast but I will probably walk across the cabin at some point for everyday seamanship tasks such as maintainance, preparation of fenders,or many other reasons during very calm conditions or at anchor and don't want to end up in the drink and calling a salvage company. Comments would be appreciated.

J

[JustSail]

It would be really hard to put the boat on its side without ballast. I've got two personal experiences that should make you feel a little better.

The first time I took my boat out I decided to NOT fill up the ballast and try out its motoring capabilities. Things worked great until I decided to make a sharp power turn. The boat healed over 25-30 degrees and I thought it was going to roll over. I eased the throttle a little and pulled out of the turn and the boat came right back up. It scared the crap out of me, but gave me a lot of confidence in the fact that an unballasted boat can go quite a ways over and still pop back up.

Another time I was up at Lake Erie and had a pulled the boat up to a dock before raising the mast. We had 3 people raising the mast and fumbling around on deck before I realized why the boat was rocking so much. I had forgotten to fill the balast tank. At no point was the boat anywhere close to capsizing.

[Newell]

Hi,

Before you have the boat, imagination and worry will be your companion. I weigh 165 and sail unballasted until the wind increases to the point it gets difficult to move around in the cockpit. I have a X and it has less fixed ballast than a M. I never motor with ballast and if I would have had ballast last Fall, I think I would have lost the boat, since I hit a rock at 8 knots. As such I'm still repairing the damage, but not a hole in the boat.

Ballast is necessary for some conditions, you're the captain, have fun.

Newell
Fast Sunday 96X, Windancer 89D

[Kelly Hanson East]

If some has a dimensioned drawing of an we could swag this pretty easily.

[Russ]

Don't worry, most power boats have no ballast and don't flip over.

You can stand on the deck and it won't flip over. I've don't this many times while rigging/raising the mast with helpers. The M also has 300 lbs of fixed ballast as well. It's a small boat and although high freeboard, it is not waiting to flip over.

If you are concerned, just fill the tanks and relax. But don't worry that standing on top of your boat is dangerous without ballast. Operating it without ballast is not dangerous if you keep people off the upper deck.


--Russ

[Retcoastie]

Also, IIRC, the video shows a stripped Mac, no engine. That leads me to believe that there is also, no battery(ies), water, coolers, food, bedding, dishes, and general junk that seems to accumulate. Of that weight, most all is below or near the water line and will add stability.

[irayone]

I have owned my Mac for about a year now....When I first got it I wanted to see it's limitations..So I took it to the lake and tried to scare the hull out of myself....I couldn't get it to tip over. But it does have characteristics of a bobbing cork. As another post stated hard turns are an issue but not a problem. I would never take the boat on the ocean without the ballast. People moving about on the boat makes the boat move about so I just tell them to sit down and hold on. I never take more than 5 persons and only like 2 people on the boat including myself. What concerns me is knock down by strong wind gusts. So I am the nut that everyone laughs at reefing at 8 knots. When my martini spills I know I am heeling way too much.

[baldbaby2000]

When motoring with no ballast be careful; if the daggerboard is down you might heel way over during a turn if you're going too fast.

I've sailed my M many times with no ballast but it really doesn't seem to be any faster. When motoring with no ballast, or having no ballast in rough seas, I'd avoid having people on the deck. Even if the boat doesn't flip over, it could suddenly shift and knock someone over the side.

As far as the physics it's pretty much a center of gravity (CG) versus center of buoyancy (CB) issue. The water ballast results in a somewhat higher center of gravity but the laws of physics don't care where the ballast weight comes from.

]

[jjan]

When motoring with no ballast be careful; if the daggerboard is down you might heel way over during a turn if you're going too fast.

I've sailed my M many times with no ballast but it really doesn't seem to be any faster. When motoring with no ballast, or having no ballast in rough seas, I'd avoid having people on the deck. Even if the boat doesn't flip over, it could suddenly shift and knock someone over the side.

As far as the physics it's pretty much a center of gravity (CG) versus center of buoyancy (CB) issue. The water ballast results in a somewhat higher center of gravity but the laws of physics don't care where the ballast weight comes from.

]

Hi,
Thanks for the reply and diagram. I fully accept and agree that stupidity, fast turns in rough seas, sailing with full sails in gales etc is a recipe for disaster and that goes without saying however, I am interested in wheather the boat will fall over in calm sheltered conditions either whilst slowly motoring or at anchor whilst unballasted with someone on top either sunbathing, preparing an anchor or hanging fenders etc or is the boat's deck area relatively safe place to be with the excercise of common sense and does my outboard act as extra ballast.

Thanks to all of you who have took the time to reply as I am enjoying this new learning experience which will hopefully make me and many others safer with our boats and the more we understand about this boat the better. I am sorry if my questions appear boring but for those of us who have never had any experience with a dual purpose boat, it's capabilities can be a bit of an enigma especially given the fact that there are so many Macgregor haters out there contributing their bit to the failings of this boat and spreading the fear of impending doom if one so much as sneezes when operating this boat. This situation is further hinderd by the party line followed at the factory when asking questions about the boat and reading the warnings in the manual. The best I can possibly hope for is to get the information from those who have similar family issues regarding safety and who have spent many tousands of hours doing what I intend to do, which is you lot. I realize that the factory has got to cover it's back but sometimes the answers given or rather lack of, don't totally inspire ones total confidence which then results in my silly questions. If anyone doubts me just ring the factory.
J

[Gerry the fish]

however, I am interested in wheather the boat will fall over in calm sheltered conditions either whilst slowly motoring or at anchor whilst unballasted with someone on top either sunbathing, preparing an anchor or hanging fenders etc

Definetely not - have done this many times with no ballast with no issues.

[Russ]

Hi,
Thanks for the reply and diagram. I fully accept and agree that stupidity, fast turns in rough seas, sailing with full sails in gales etc is a recipe for disaster and that goes without saying however, I am interested in wheather the boat will fall over in calm sheltered conditions either whilst slowly motoring or at anchor whilst unballasted with someone on top either sunbathing, preparing an anchor or hanging fenders etc or is the boat's deck area relatively safe place to be with the excercise of common sense and does my outboard act as extra ballast.Thanks and the same to all others who have took the time to reply as I am enjoying this new learning experience. which will hopefully make me and many others safer with our boats.
J

We bought our Mac without ever standing on one, so I know exactly what you mean. There is so much of the unknown. Best to ask a question and get peace of mind.

Short answer: No, the boat can't tip over because it's without ballast with someone on the deck. It's very stable without ballast.

A couple of people on the deck during docking/rigging is very common and no Mac has ever become unstable and/or tipped during normal operation. Rigging takes a lot of hands on deck without ballast and the boat doesn't lean or tilt when we hang over the side to grab a line.
I'm fairly sure if you pulled it over by the shrouds it would pop back up but I've never tried (maybe I'll try tomorrow and let you know). The ballast is mainly to add stability and pull the boat back when the wind wants to push it over. It is not to keep the boat upright while at rest or motoring.

I know where you are coming from. All the reading and talking I've done about ballast freaked my son out. Last year (when we got the boat) we filled the ballast and left it. Done. Then I decided to empty it and see how fast we can go. My 10 year old son was on the verge of tears at the thought of removing the ballast. "No, no, no, don't empty the ballast." he said. He thought the boat was unstable without and would flip over. It is a tall boat and that seems like a logical conclusion. To his delight, we ran the boat sans ballast for a week and he didn't notice this year. It's a little tipsy, but that's probably because it sits higher up (3 inches) without the ballast. The Mac won't tip over. This is something you must understand and accept else your confidence will be hampered.

Of course as mentioned above (and in the manual) don't run over 6mph with the dagger board down. It acts like a hydroplane and can be dangerous. I've done it and when I felt the boat doing that, throttled down and pulled the board up. There are thousands and thousands of MacGregors afloat and if they flipped like a sunfish nobody would get on one.


--Russ

[jjan]

Hi,
Thanks for the reply and diagram. I fully accept and agree that stupidity, fast turns in rough seas, sailing with full sails in gales etc is a recipe for disaster and that goes without saying however, I am interested in wheather the boat will fall over in calm sheltered conditions either whilst slowly motoring or at anchor whilst unballasted with someone on top either sunbathing, preparing an anchor or hanging fenders etc or is the boat's deck area relatively safe place to be with the excercise of common sense and does my outboard act as extra ballast.Thanks and the same to all others who have took the time to reply as I am enjoying this new learning experience. which will hopefully make me and many others safer with our boats.
J

We bought our Mac without ever standing on one, so I know exactly what you mean. There is so much of the unknown. Best to ask a question and get peace of mind.

Short answer: No, the boat can't tip over because it's without ballast with someone on the deck. It's very stable without ballast.

A couple of people on the deck during docking/rigging is very common and no Mac has ever become unstable and/or tipped during normal operation. Rigging takes a lot of hands on deck without ballast and the boat doesn't lean or tilt when we hang over the side to grab a line.
I'm fairly sure if you pulled it over by the shrouds it would pop back up but I've never tried (maybe I'll try tomorrow and let you know). The ballast is mainly to add stability and pull the boat back when the wind wants to push it over. It is not to keep the boat upright while at rest or motoring.

I know where you are coming from. All the reading and talking I've done about ballast freaked my son out. Last year (when we got the boat) we filled the ballast and left it. Done. Then I decided to empty it and see how fast we can go. My 10 year old son was on the verge of tears at the thought of removing the ballast. "No, no, no, don't empty the ballast." he said. He thought the boat was unstable without and would flip over. It is a tall boat and that seems like a logical conclusion. To his delight, we ran the boat sans ballast for a week and he didn't notice this year. It's a little tipsy, but that's probably because it sits higher up (3 inches) without the ballast. The Mac won't tip over. This is something you must understand and accept else your confidence will be hampered.

Of course as mentioned above (and in the manual) don't run over 6mph with the dagger board down. It acts like a hydroplane and can be dangerous. I've done it and when I felt the boat doing that, throttled down and pulled the board up. There are thousands and thousands of MacGregors afloat and if they flipped like a sunfish nobody would get on one.


--Russ

Hi,
Thank you for that brilliant straight to the point answer, it was exactly what I needed to hear. You have given me excellent practical real world information which I now fully understand. I think you should try for a job at the Macgregor factory as you would certainly alleviate much of the uncertainty around this issue. At least your answer is based on your experience and not just the desire to cover your back.
J

[daydreamerbob]

You are going to have a blast with this boat...during the last year - i have done some stupid and probably crazy things on this boat - we tube alot and sharp turns are a necessity to get the kids some wake to jump...with consideration we have done very very well...

anyway - just recently we were out with 4 adults - 1 kid at about 140, 1 kid at 100, and three smaller kids - some in the cockpit some on the deck and a 200 pounder making his way to the head - while we were WTO no ballast - i lost control of the boat and had a tough time getting it back - if you think about it 300# of lead versus lots of flesh up high moving around changes the center of gravity - i was afraid for the first time since owning this great boat---my advice - operate within the stated parameters until you get comfortable - then incrementally see what she and you are capable of ---

I am pretty sure that if you sail unballasted with 6 adults on the deck you are going over ---

I am also pretty sure that if you are ballasted - you can ride through some pretty rough chop with guests on the deck and even with waves across the beam and be fine - scared maybe but safe...

do not stretch too far too soon - but have fun every time you are out...

[irayone]

Boats don't have the problem .....People do...Most accidents happen from adult beverages and lack of life jackets.

[SkiDeep2001]

I just rode my 21 speed mountain bike 8 miles round trip (It's 2AM) to my local Chinese restaurant so I could have 2 Electric Ice Teas and that was going to be my limit, last time I had to call a cab for trip home because I threw a couple Bacardi Cokes on top and was car bait. Only 4th time drinking due to DUI in August of 07. I do not drink while boating anymore because you can go to jail for BUI just as easily as DUI and get upside down real quick. As far as crashing and burning it can happen even if dead sober, boats on the water are accidents waiting to happen. We do all we can to educate ourselves but boating throws you curve balls like you would not believe. A stone cold sober experienced boater can be in a world of hurt so fast it should scare the **** out of you. Been there done that,as I'm sure many of you have. I was working on my CB and rudder trying to figure out how to get back to dock safely without hitting another boat and S/V Nikita hailed me on my new floating handheld VHF which I had no clue after reading directions, channel 69 is public channel? and get your new Ocean Series Hydrostatic vest on while hanging over stern or my cat who has his vest on may be skipping my boat. Remember, I'm one who almost went over a waterfall because of boat confusion and we were all on our toes. I don't want to say I am afraid of my but I have a healthy respect for what can happen to it/me, only because I am a 40 year powerboater and I am still learning the Mac curve and they will always be 2 different beasts. I don't want to scare a new boater needlessly but I will always give a heads up to the newbie to have a very healthy respect for any water sport you are new to. You can have many enjoyable hours of fun but keep in mind it only takes a microsecond of time to go wrong. Now go out and have fun. I may have to edit this in the morning but what the hey, I call em as I see em at the time and I am seeing OK right now, not sure about thinking. (And I only had to correct spelling/punctuation a couple of times.) ZZZZZZZZZZZZZZZ Rob