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Old 09 December 2014, 04:59   #11
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Titanic compared to Modern cruise ship.
What a difference a century makes...
Recently saw one of the new mega cruise ships docking in Long Beach, just behind the Queen Mary. No idea which one as it was Dark'O'Clock but she was about 3 times the size of the QM but with less than 1% of her character.

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Old 09 December 2014, 11:27   #12
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...until someone worked out that boats are heavier in fresh water, load a boat in sea water to the gunnels and when it enters fresh water, down she goes.
To be accurate, "less buoyant" rather than "heavier".

Sea water weighs more than an equal amount of fresh water (due to the dissolved salts), so a given weight ship will displace less sea water than fresh, thus riding higher in salt water.

Shows up in small boats as well, as a slight reduction in top speed when going from salt to fresh water.

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Old 09 December 2014, 11:52   #13
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Hmm didn't know about the slight speed reduction in fresh water, figures tho. that means I might be able to get 42 knots!!
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Old 09 December 2014, 12:32   #14
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Originally Posted by jyasaki View Post
To be accurate, "less buoyant" rather than "heavier".



Sea water weighs more than an equal amount of fresh water (due to the dissolved salts), so a given weight ship will displace less sea water than fresh, thus riding higher in salt water.



Shows up in small boats as well, as a slight reduction in top speed when going from salt to fresh water.



jky

6 and 2x3 and half a dozen


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Old 09 December 2014, 12:44   #15
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6 and 2x3 and half a dozen


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'er Biff - you knew that from your Diving days: freshwater=less lead.

Cheer up mate - at least if you drown in freshwater now, you'll know it isn't because you're heavier, but rather less bouyant
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Old 09 December 2014, 15:22   #16
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Yeah you're right, we used to have to calculate the buoyancy to lift things from the sea bed but still had to work out how much it weighed to crane it on board, so to me it didn't really matter if it was heavy or less buoyant.


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