Ballast vs. boat max weight capacity?

[WABoating]

I see people here with 2000+ pounds of ballast. Add some people and you're talking a LOT of weight. Do you stay within the rated weight capacity (as shown on the capacity plate) of the boat, or do we just sort of "wink and nod" at those numbers?

Example: My current 20 foot boat has a rated capacity of 1440 pounds. If I toss 1000 pounds of ballast in there, I can only carry 2-3 adults. But I hear of people with twice that much ballast and a boat full of folks.

What's the story?

[zad0030]

Those numbers are iffy in the way they are calculated. It's obviously not the recommended seating capacity nor isn't the max payload. But the coast guard just gives..... Well I don't know.

[ajholt7]

No one pays attention to the rated weights. Many load up way beyond that.

[jbort]

Also different boats have different capacity. My 07 22Ve is rated at 1900+. I'll bet 24Ve is more. Maybe someone will comment on how the wt. capacity is determined.

[WABoating]

No one pays attention to the rated weights. Many load up way beyond that.

That's the impression I get, too. What made me wonder is studying the (Mercury) exhaust system for my current boat. The boat design and installation manual very clearly gives maximum waterline heights for the mufflers; they must be installed in the boat so the waterline does not go above a certain point. I believe this is to prevent water from backing up through the exhaust system into the engine itself.

Another one is the height of the fuel tank vent on the side of the boat. It's a certain distance above the waterline. It does not have a "loop" in its hose like the bilge pump does, so it doesn't have the same protection from incoming water. Were I to load down the hull too much, it would be entirely possible to splash that vent or even put it below the waterline, possibly introducing water into the fuel tank.

These things made me wonder if the listed max weight is somehow related to, or allowed for, in the design of things like that. And if you exceed it, what systems you are putting at risk. Yes, the hull may not sink - but water in the fuel tank or engine isn't exactly desireable either.

And that, finally, led me to wonder if dedicated wakeboard boats - which are known to carry lots of ballast - had higher ratings and/or different layouts to accommodate all that weight. Or maybe folks just ignore all of it, load up, and hope for the best.

[somebodyelse5]

If sure the capacity has to do with how stable the boat is and how it can handle certain obstacles while still keeping certain characteristics, does that make sense? I read somewhere that our boats are a certain class of inland waterways yada yada and it meant the boat could handle Xft waves and X Force Winds. Im sure to qualify in that class is must be able to maintain a set standard.

I know with my boat loaded down i have to be really careful around rollers, and when its sacked out I need to watch the nose when a rider falls, have to throttle down slower.

[somebodyelse5]

That's the impression I get, too. What made me wonder is studying the (Mercury) exhaust system for my current boat. The boat design and installation manual very clearly gives maximum waterline heights for the mufflers; they must be installed in the boat so the waterline does not go above a certain point. I believe this is to prevent water from backing up through the exhaust system into the engine itself.

Another one is the height of the fuel tank vent on the side of the boat. It's a certain distance above the waterline. It does not have a "loop" in its hose like the bilge pump does, so it doesn't have the same protection from incoming water. Were I to load down the hull too much, it would be entirely possible to splash that vent or even put it below the waterline, possibly introducing water into the fuel tank.

These things made me wonder if the listed max weight is somehow related to, or allowed for, in the design of things like that. And if you exceed it, what systems you are putting at risk. Yes, the hull may not sink - but water in the fuel tank or engine isn't exactly desireable either.

And that, finally, led me to wonder if dedicated wakeboard boats - which are known to carry lots of ballast - had higher ratings and/or different layouts to accommodate all that weight. Or maybe folks just ignore all of it, load up, and hope for the best.

I think in the future it will become more of a norm for boats to be engineered to carry the weight they do and produce a more desirable wake. It seems like we are getting to the point where we all are really expecting more out of these boats. I bet we start seeing boats the seriously out perform the previous models, not just more blingy electronics, features that actually are useful and are intuitively set up. Its as if the wakeboat industry has been riding the same ideas for so long, sticking with the basic runabout and slowly tweaking things, bigger motors to be able to move the weighted boats, make a boat that works all around, simple things like that. I dont know about you guys, but the only time I dont have my boat sacked out is when its going on/off the trailer, its never used for skiing, never used for tubing, its never used for transportation, its a dedicated surf/wakeboard boat. To me there is a much larger market these days and the engineers are starting to see that, I want to be a marine engineer and I have some kickas$ ideas that I think people would be all over, and we should hopefully see some cool innovations. I hope I can make it there before it happens, so I can be a part of it. I would rather the the wake producing aspect of the boat take precedence over the "all around family boat" aspect of the design approach.
Its time for a big paradigm shift in the industry :ro:

Idk if that was the right place for that, but what do you guys think?

[ragboy]

First, the amount of ballast capacity, and the amount used at one time are 2 different things. My boat has about 3000 lbs of ballast available, but at most, I will have 1600 or less filled up, since we surf only on one side.

Also, keep in mind, that water ballast is very different than lead or steel or whatever. If you started taking on water, you can pump out your ballast quickly, and it is neutrally buoyant. You start taking on water, that lead may take you down quick.

Also, water conditions are everything. If it is very rough, be very careful how you load your boat down. Common sense goes a long way.

I think the future, will be something more along these lines:

http://www.lowriderboats.com/

But its going to take a gutsy manufacturer to start testing something like that. Maybe a long time from now.

[Ewok]

I think the future, will be something more along these lines:

http://www.lowriderboats.com/

But its going to take a gutsy manufacturer to start testing something like that. Maybe a long time from now.

That looks very much like the power wedge, just tunable from side to side. I bet some manufacturer already had patents for this type of hull design but it looks very interesting, I wonder how clean a wake that would produce.

[ragboy]

Seems more sophisticated than a power wedge, and side to side makes it work for surfing. And there isn't a huge piece of steel hanging off the back of your boat.

[somebodyelse5]

Seems like you need to get patents on your ideas now, any you may have, cause i had an idea similar to the low rider idea and its covered under their patent. never even seen the low rider. Keeping my remaining ideas locked up :)

[ragboy]

Y, larry mann is behind that, and he has been working on it for a long time.

[twinturbostroker]

Here is a link to general information regarding the USCG loading capacity plates.

http://www.boatus.org/onlinecourse/reviewpages/boatusf/pdf_files/info1a.pdf

[somebodyelse5]

Y, larry mann is behind that, and he has been working on it for a long time.

Im talking about other ideas man....

[ragboy]

Im talking about other ideas man....

Well get cranking on them dude. ;-)

[somebodyelse5]

Well get cranking on them dude. ;-)

gotta get a few degrees outta the way first, Mechanical engineering then masters in marine engineering...but they are in the works my friend dont worry.