Response to the MB ballast issue

I have read several posts regarding why Mb Sport boats hold more ballast weight than other boats in the same size category and I would like toput some of the myths about this issue to bed.
The amount of ballast a boat can carry has nothing to do with the foam in a boat. Think about it. Do big cargo ships have foam filled centers so they can hold more merchandise? No, that would be silly. The way the amount of ballast weight a boat can safely handle is determined was explained to me like this...Inside of a boat there is a sort of "chasis" like in a car. Every boat has a chasis. Most boats chasis are about 7" deep. The equation that gives you the safe amount of ballast weight is the depthe of the chasis multiplied by the length of the chasis multiplied by width of the chasis. Take that number and multiply it by the "magic number" 231 and multiply that by 8.5 which is the weight of water and that is the amount of water weight your boat can hold.

DxHxW=X
Xx231=gallons of water x 8.5lbs= Max weight

MB makes their chasis 5" deeper than the average boat so therefor they can hold more weight. Once again though the depth of the chasis is not the depth of the boat, the chasis is the structure inside the boat below the floor.

Wow that was a mouthful and sounded a lot like a ninth grade Algebra lesson...sorry

Five feet deeper? Hmmmmm......

' = feet, " = inches

lol. Why, yes it does. My bad.

believe me I thought the same thing when I read her post... I then read yours and said ...aaaaahhhhh

Rebecca ~ that is the same thing the MB guys told my boy and I. So he measured the MB 21' and measured his 21' X2 and they are the same. What I have been told also is any boat over 20' does not have any weight restrictions, so if MC, CC, BU or any other boat manufacture can put that much weight in there boats, but chose not to. Some of the reason I have heard for them not putting 2000 plus LBS is the wear and tear on the motor and tranny, the safety issue of having a boat with 2000 plus LBS in it. IMO I think that MB is saying "F" it and trying to get there name out there as much as possible. Hell last year they said they had the best boat/wake around and this year they all ready changed that hull. All in all I think MB is a very nice boat and has great potential.

Actually, I think internal ballast restrictions have to do with Manufacturers Association (NMMA) certification more than anything else. I don't know what formula they apply to determine max capacity, but that's my guess.

I was reading WB magazine the other day and a Malibu add said they had the most standard ballast of any boat at 1250 lbs. MB has 2500 lbs standard? Maybe someone should tell Malibu

That issue is discussed here: http://www.wakeworld.com/MB/Discus/messages/3183/210438.html

Somehow, I left off the "National Marine" part of NMMA.

I was wondering were the NM part came from

Ant Bug~ When you said you measured The MB and then measured an X2 how and where did you measure? You would have to go below the floor under the drivers seat, and I knoe on my MB that would mean pulling the floor. Your best bet would be to E-mail Mike Brendel (thats who gave her that info) info@mbsports.net

I personally think how a boat responds to ballast is more important than just how much ballast it holds.

If a SAN makes a bigger wake with 800 lbs than a B52 with 2000, who cares that the MB carries more ballast?

It's a negative to me if a boat needs that kind of ballast to get a good wake. Fuel mileage will go to hell, handling, etc.

I don't think you can just look at the amount of ballast a boat holds and get much from it.

So Micah how many guys you know just stick with the stock ballast on their SAN without adding sacs or lead?

So where are we getting this thing about weight restrictions? The rules are simple (as I am told) there has to be a seat for everone in the boat. That becomes the capicity of the boat. Some manufactures will say they can seat 12 or whaterver. But what happens if you have 12 corn fed country boys in the boat? I don't think that you will seat them all, at least comfortable. So if there is not a SEAT (key word) for them then the capicity will change. Yes the weight for the boat to stay afloat is a consideration in weighting a boat. I believe (just my thought) that factory ballast weight is determend by what the manufacture believes will still alow the boat to safely perform in the water. Any one can add 2500 lb of weight but what are you going to loose as space, and where will the performance of your boat go? MB just happens to have found the room to add it and believes that they are not sacrificing performance or it becomes another selling point for them.

I was making a general statement, and just used the SAN as an example of a boat that doesn't need much ballast. I don't own one.

Do you think a SAN with 2500 lbs, or a B52 with 2500 lbs would make the biggest wake?

That's my point. I doubt you'd need 2500 lbs in a SAN to make the same size wake as a B52 with 2500 lbs.

Ballast weight alone is almost meaningless to compare.

I will add some comments as a manufacturer.

This can get rather complicated but I will try to make it simple. There are 3 major organizations when it comes to rules and regulations for boating. They are the US Coast Guard (USCG), the American Boat and Yacht Council (ABYC), and the National Marine Manufacturers Association (NMMA). The USCG has a Code of Federal Regulations (CFR) which are required laws that all manufacturers have to meet. The ABYC is a group that takes the CFR's and adds to them best practice methods and created standards and technical reports which create an even safer boat. However, the use of these standards are completely voluntary. The NMMA is an additional group which uses these standards and will actually certify manufacturers according to whether they meet the ABYC standards or not. Again, this is a voluntary process for each manufacturer and costs money and time.

A good example of how this works is in capacity calculations. For the USCG, only boats under 20 feet have regulations that require capacity calculation. For the ABYC, it is required on boats less than 26 feet. While there are many equations and formulations for calculating weight capacity I will try to make it easy to understand. Basically to calculate capacity you have to calculate the volume of the boat below the static float plane. The static float plane is a plane that starts with where water can enter the boat in the forward most part of the boat and where water can enter the rear most part of the boat. Basically you draw an imaginary line from the top of the bow of the boat and the top of the transom (or vent if the vent is below the transom) and then calculate the volume below this line. That is how you calculate the total cubic capacity of the boat.
The weight capacity is determined by converting this cubic capacity (volume) to the weight of water it would displace, subtract the boat weight, and permitting one pound of load capacity for each seven pounds of remaining displacement. Obviously there are safety factors that go into the equations and formulations but that is how you calculate the total weight capacity. The person capacity is calculated by adding 32 to the total weight capacity and then dividing that by 141 (average weight of person). (Example - total capacity is 1500 lbs. Add 1500 + 32=1532 Then divide by 141= 10.8 or 11 persons) Then you can only claim as many as you can seat safely. That may be too much info for some of you, but that is how the standards read.

So as you can see, the amount of foam, chassis heights, or any of the other speculations have nothing to do with ABYC calculations. Foam is important but that applies to Floation, which is another ABYC standard, but not capacity. I have no idea what the chassis height is all about.

At Skiers Choice, all of our boats are NMMA certified and have met all these standards for capacity and flotation (we pass standard flotation requirements which are actually not required yet). Again, this process is voluntary not mandatory and many smaller manufacturers do not meet these higher safety standards. Each NMMA certified boat will have a sticker on it and is required to calculate capacities in this manner. An example of this is our new Launch 24 SSV which has a 1800 lb ballast system as standard. The NMMA approved capacity on that boat is 2300 lbs, so offering a 1800 lb system still allows us a driver and passenger and still be under capacity. It is our decision not to offer ballast systems that exceed the capacity of the boat. Each manufacturer may vary on that decision.

Hope that at least clears up how you calculate capacity from the ABYC and NMMA standards.

I have two issues to follow up on this.

1.) Try to sink a fat boat and you're gonna need 2500lbs. So, in my mind that 2500lbs in an MB is probably equivalent to 1200lbs in any other narrow boat. Fat boat = hard to sink = more gas
2.) With all that internal ballast, that doesn't leave much area left over to provide flotation to below the floorboard stringers. So, does the boat float if it takes on water? Who knows. I do know that I've heard stories about X boat manufacture having water up to the deck, ie basically swamped and still floated.
Is this important? Again, who knows. Would I want to be in any boat that was swamped or going to sink, NO and h*ll NO.
Where does this leave us? It's all subjective. What you want, how you like the dealer, what you feel is best bang for the buck, how you like the wake, etc, etc, etc.

Chris
Get the Grip you Deserve
www.wakejunky.com

Matt ~ thanks for the post. very interesting.

If my boat gets water up to the deck or rub rails I hope it sinks. Its gonna be a total loss anyway. Most people haven't ever seen a ski boat sink to the rub rails. Unfortunately I have. I don't care how much foam is in a boat they have a tendency when filled with water to turn over. Sure they don't sink, but it's still upside down. I guess in a best case scenario the boat would fill through a hole in the floor and evenly, then not have any rollers to turn it over, but where we ride we are more worried about getting swamped by yact rollers which immediately turn a swamped boat over.

That said. I saw that Malibu ad and laughed. I think a lot of boats don't add more weight for liability reasons. The MB is a big boat and can handle the weight without major side effects.

Gas mileage? Here's another point about big boats. I'm not an engineer, but a bigger boat sits higher in the water and creates less resistance than a small boat sitting lower. Adding weight to a big boat will sink it in a similar way to a smaller boat. You will consume a small amount more fuel, but it's not as significant as you may think. Making a wake is a function of moving water. The more you move the bigger the wake. The inverse is true of gas mileage (minus additional weight for accel/decel): The more water you move the worse your gas mileage.

My 2 cents. Maybe I'm all wrong, but this is from my experience. I've been fortunate enough to ride behind almost everything out there, including both size MB's.

Ant Bug, where do you get the idea that MB is a "big Boat" it wasn't the giant boat rotating in the middle of the MC booth at Pleasanton...both the 21 and 23 are only 96" (inches not feet) wide. If anyone is considering the purchase of a new ski or wakeboard boat I would love to take you on a demo in the MB and allow you to see how well these boats handle with the ballast tanks both empty and full...or even half full (baffled tanks in the MB make for a great ride even half full)

when are you taking your boat out?love to get a pull and see exactly what you mean!

SANTA rosa is not that far.lol

Ed, I'm sure Rebecca or her brother will be at the Delta once in a while so maybe they can hook ya up. They are both really cool about giving people (Me) pulls all the time.

Jeremy is out at Sonoma with the boat today, he is nuts, the weather sucks today! I am a fair weather boater, I'll take you boys out once the weather gets a little nicer, until then you'll have to try to hook up with my brother for a ride.