fresh /saltwater formula

[Charlie99]

OK. We should put a link to the last few posts in the "You Don't Have to Quote" whine and cheeze.

Sometimes quoting helps a lot.

ES601, in his last post, is just referring to the effect of temperature on the amount of lead needed.

 

[Thalassamania]

Sometimes quoting helps a lot.

I think part of the problem is that some of us work in threaded mode and other's do not. But you're right ... quoting can help keep on track. Are we going to go into the pressure effects and potential density?<G>

 

[LI Diver]

OK. We should put a link to the last few posts in the "You Don't Have to Quote" whine and cheeze.

Sometimes quoting helps a lot.

ES601, in his last post, is just referring to the effect of temperature on the amount of lead needed.

Sorry guy's I've been having problems w/computer shutting down scubaboard everytime I attempt to quote. :shakehead I Went across the office to another computer to make this post. If anyone has any advice how I can get my functionality back on the other machine I'm all ears!!!!!!!!! I've been to the site support forum and saw the link but they say you have to call microsoft about it to get the hotfix.

 

[LI Diver]

I think part of the problem is that some of us work in threaded mode and other's do not. But you're right ... quoting can help keep on track. Are we going to go into the pressure effects and potential density?<G>

Sorry Thal! And NO WE ARE NOT thats why they make BCD's thank you very much!

 

[Thalassamania]

If you're using a BC to solve the change in density of water due to pressure you're diving a LOT deeper than I am.<G>

 

[cool_hardware52]

Ok guys what was that formula again?? If it takes 5LBS of weight to sink my new wet suit in fresh water then how much do I need to sink it in salt water??? And this does work right ??? If I know exactly how much weight I need in a bathing suit alone and then put on this wetsuit with the weight needed to sink it in my pool plus the salt water differential I should be dialed right in.... or pretty close anyway right?
Thanks guys!

es,

When you say it takes 5lbs to sink you suit is that just the suit or is that you in the suit?

If it's just the suit you can ignore the difference between fresh and salt water. Why? because it will be so small as not to matter.

A handy rule of thumb is "1lbs difference between fresh and salt for every 40 lbs of diver and gear"

Example if you have a 180 lbs diver wearing 60 lbs of gear you have 240 lbs or diver and gear. 240 / 40 = 6 ~6 lbs That about what will be necessary between fresh and salt.

What does just your wetsuit weigh? Maybe 5 lbs? 5/40 = .125 A 1/8 of a lbs can be ignored.

OTOH, if the you were wearing the suit when you determined it requires 5 lbs then it can't be ignored. Say you are 155 lbs + 5 lbs of wetsuit for a total of 160. 160/40 = 4 lbs.


Tobin

 

[cool_hardware52]

If you're using a BC to solve the change in density of water due to pressure you're diving a LOT deeper than I am.<G>

Ya no kidding. As taught in High School physics liquids are considered to be incompressible. For water that's true, up to a point. Something like .005% per atmosphere.

My water jet pump pumps to 67,000 psi. (Trust me the plumping used is unique) At about 30,000 psi the effect becomes sufficient to affect the process, and supply pumps need attenuators to avoid pulsations.

30K psi would be deeper than 67,000 ft!


Tobin

 

[LI Diver]

es,

When you say it takes 5lbs to sink you suit is that just the suit or is that you in the suit?

If it's just the suit you can ignore the difference between fresh and salt water. Why? because it will be so small as not to matter.

A handy rule of thumb is "1lbs difference between fresh and salt for every 40 lbs of diver and gear"

Example if you have a 180 lbs diver wearing 60 lbs of gear you have 240 lbs or diver and gear. 240 / 40 = 6 ~6 lbs That about what will be necessary between fresh and salt.

What does just your wetsuit weigh? Maybe 5 lbs? 5/40 = .125 A 1/8 of a lbs can be ignored.

OTOH, if the you were wearing the suit when you dtermined it requires 5 lbs then it can't be ignored. Say you are 155 lbs + 5 lbs of wetsuit for a total of 160. 160/40 = 4 lbs.


Tobin

No just the suit

 

[LI Diver]

If you're using a BC to solve the change in density of water due to pressure you're diving a LOT deeper than I am.<G>

oops ............. my bad! Must have been thinking of the volume of the air in my bc and wetsuit (and body cavities ) compressing at depth and making me as a unit more dense (which I've been told is not possible).So:mooner:
:lol:

PS only jokin you know I love you guy's!!!!!

 

[Thalassamania]

As observed above, water is actualy compressable, enough so that those who do Physical Oceanography (not my best class in Grad School) have to figure that compression into their calculations of potential density (trying to figure out which way a water mass is headed, up or down).