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Old 14-03-2013, 09:38   #31
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Re: Displacement???

As has been said here before. Depending on the specific gravity of the water you are in, you will displace more in fresh water than salt. It has to do with the total gross weight of the vessel at the time of the measurement, it will displace an amount of water equal to that weight. Which makes me wonder, if you took all the boats out of the ocean, would the sea level rise or fall?
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Old 14-03-2013, 09:43   #32
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Re: Displacement???

Fall.
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Old 14-03-2013, 09:51   #33
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Re: Displacement???

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Originally Posted by captain58sailin View Post
As has been said here before. Depending on the specific gravity of the water you are in, you will displace more in fresh water than salt. It has to do with the total gross weight of the vessel at the time of the measurement, it will displace an amount of water equal to that weight. Which makes me wonder, if you took all the boats out of the ocean, would the sea level rise or fall?
Just to clarify, in fresh water the boat will displace a greater Volume of water, the Weight of water displaced will be the same be it in Fresh, Sea water or brakish water.
Its all pretty much academic. Unless you go to the bother and expense of getting hydrostatic data for the boat hull, and then have draught marks cut in fore, aft and midships, you cannot work out the displacement.
Boat builder will have a good stab at with a computer model, but if you want an accurate weight of the boat, best to use crane fitted with a load cell.
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Old 14-03-2013, 10:02   #34
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Re: Displacement???

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Thanks for all the enlightening answers. I gather from them that there is no standard formula that builders adhere to when publishing the displacement weight of their boats.
Yep. That's the simple, direct answer to your question. There is no standard.

Of course, this wouldn't be the internet if the answers that didn't even come close to addressing what you were asking didn't outnumber the simple, direct answers by at least 10 to 1!
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Old 14-03-2013, 10:20   #35
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Re: Displacement???

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Thanks for all the enlightening answers. I gather from them that there is no standard formula that builders adhere to when publishing the displacement weight of their boats. Thats really all I wanted to know. I kinda thought that most people would assume, since I was using a computer, that I was of normal intelligence and consequently would know all the elementary stuff, volume of water displaced=weight of displacing object, etc. Still, I did learn what I wanted to know. CF is a great resource.
Yes, the published numbers for boats and the real numbers often vary by quite a bit... if travelift weight measurement is to be taken as somewhat accurate....
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Old 14-03-2013, 10:48   #36
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Re: Displacement???

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CF is a great resource ... no doubt ...

That is correct, even better....

Every time I come to this forum I have more fun then watching Forrest Gump movie.
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Old 14-03-2013, 11:03   #37
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Re: Displacement???

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Fall.
Well ... in the spirit of this topic ... one has to account for the gravity force of moon and sun. So, the answer depends on time and location ...
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Old 14-03-2013, 11:05   #38
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Re: Displacement???

I just wondered how this could have some many replies, we will debate anything here

Now for a REAL question; if you drink all the beer out of the cooler on the boat does the boat displace less than when they were in the cooler?
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Old 14-03-2013, 11:11   #39
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I just wondered how this could have some many replies, we will debate anything here

Now for a REAL question; if you drink all the beer out of the cooler on the boat does the boat displace less than when they were in the cooler?
Displaces the same until you piss it over the side.
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Old 14-03-2013, 11:12   #40
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Re: Displacement???

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Now for a REAL question; if you drink all the beer out of the cooler on the boat does the boat displace less than when they were in the cooler?
It depends ... LOL

Have you pied already between the time you drunk all that beer and the time you asked this question? And ... where have you pied?
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Old 14-03-2013, 11:17   #41
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Originally Posted by captain58sailin
Which makes me wonder, if you took all the boats out of the ocean, would the sea level rise or fall?
Floating boats out of the ocean? Sea level will not change.

Sunken boats out of the ocean? Sea level will drop.

But what happens when you remove the lead from your keel and throw it overboard? (Your boat is floating, not sunk)
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Old 14-03-2013, 12:17   #42
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Re: Displacement???

The reason you displace more fresh water than sea water, is sea water has greater density. Like my head.
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Old 14-03-2013, 12:34   #43
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Re: Displacement???

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Originally Posted by Jimbo485 View Post
Floating boats out of the ocean? Sea level will not change.
Sure it will, it will drop!

Quote:
Originally Posted by Jimbo485 View Post
But what happens when you remove the lead from your keel and throw it overboard? (Your boat is floating, not sunk)
Sea level will drop.
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Old 14-03-2013, 12:40   #44
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Re: Displacement???

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Originally Posted by Jimbo485
But what happens when you remove the lead from your keel and throw it overboard? (Your boat is floating, not sunk)

Sea level will drop.
Sure, it will stay the same ... LOL

This is the best topic I have read in a loooooong time ...
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Old 14-03-2013, 12:45   #45
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Re: Displacement???

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Sure, it will stay the same ... LOL

This is the best topic I have read in a loooooong time ...
Clearly we need a poll!
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