I have just bought a wet suit for some fairly cool water diving, i went to a friends pool this weekend to make sure that all my gear check out okay, everything worked great except that I couldn't sink. The local scuba store operator suggested that I ad six pounds to my weight belt and I did but I still couldn't sink, the wet suit is a 6.5 mm and a fiarly cheap one, but still this brings my weight belt up to around 12lbs, how much am I going to have to ad to sink?
wetsuit
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bio guy
Guest
I used to use about 24-28 lbs on my full wetsuit, hood and gloves. It was a coldwater Brooks (6-7 mm??), with 3/4 top over farmer john. (At the time using exclusively BC, so no weight added by backplate, and in freshwater) I definitely wasn't overweighted at 24 lbs. Most dive shops seem to be really good about weights, so you should be able to bring at least a rental belt home and try out different combinations of weights to find what you need.
Oh, and welcome to the site. Jump into any of the threads. There is always something to learn.
Oh, and welcome to the site. Jump into any of the threads. There is always something to learn.
large_diver
Contributor
Hi Andy,
One rule of thumb that many instructors seem to use is to take 10% of your body weight and add 10 lbs. I use a 7mm farmer john/jacket (Bare). I am 260 -- using the calc. above yields 36 lbs -- I currently use 40 in salt water(probably due to my "newbieness").
Hope this helps.
One rule of thumb that many instructors seem to use is to take 10% of your body weight and add 10 lbs. I use a 7mm farmer john/jacket (Bare). I am 260 -- using the calc. above yields 36 lbs -- I currently use 40 in salt water(probably due to my "newbieness").
Hope this helps.
That 10% rule can be downright dangerous and lead to drastic overweighting. It applies to a very narrow set of circumstances.
It takes trial and error to determine proper weighting. Ad far as a new wet suit, you cna wrap a weight belt around it and keep adding weights until it sinks. Then add that amount of weight to what is needed without a wet suit. There's more information at http://diverlink.com/newdiver/buoyancy.htm that can help.
It takes trial and error to determine proper weighting. Ad far as a new wet suit, you cna wrap a weight belt around it and keep adding weights until it sinks. Then add that amount of weight to what is needed without a wet suit. There's more information at http://diverlink.com/newdiver/buoyancy.htm that can help.
How much you need will depend greatly on your body type,size and the wetsuit it'self. I use a 2 piece 7mm ( ls top and farmer john and I am 5'9 150lb) and I use about 18lb in fresh water. Don't just add the weight and jump in. Try using the 12lb you already have on your belt and have someone hand you additional weight, hold it close to your chest and see what happens, that way you drop it if necessary, Continue adding weight until you get to the amount you need. As you can see from the other post, it may well be 20 or more lbs. Be aware of 2 things that effect wetsuits. First, there is a good bit of trapped air in the suit and it will come out at depth which will decrease the total bouyance of the wetsuit and the wetsuit will compress at depth, reducing it's bouyancy even more. And when you finish a dive, do a GOOD bouyancy check to see how close to ideal your weight is and LOG IT COMPLETELY!! Including the exact wetsuit, water conditions, weight, other relevent equipment like hoods, tank type and weight comments, ie too much weight, just right ect. I do this on the first couple of dives each year and every time I change equipment. As a result, I can look at dive conditions, determine exposure suit requirements, find a similar dive and have the exact weight I need every time.
mlove
Contributor
I like your plan of carefully logging all dive data, but how does dive conditions effect buyancy?
M
M
jobowker
Guest
The list of equipment that you have, what wetsuit you're wearing, and fresh vs salt water all factor in to how much weight you need. I think that's what he meant by things to note after the dive that would affect your buoyancy. The other stuff (weather, temp, etc.)is just for your own edification. I just recently bought a new wetsuit (7 mil, same as old one) but needed to add another two pounds to get down. That brings my total up to 30 pounds of lead on the belt. I cannot get down with any less weight, even with letting most of the air out of my lungs and my BC completely empty, so I think I'm pretty close to the ideal weight for me. I'm 5'8" 155 lbs. IMHO, I'd rather be slightly overweighted than underweighted. If I were to take any weight off, I wouldn't be able to stop at 15 feet and the end of my dive when my now buoyant tank doesn't help matters. I say go a little heavier than you need, and then reduce as your experience grows until you reach your ideal weight.
Go to a swimming pool with all your stuff. See how much weight it takes to sink each piece of stuff. Write it down. Also, using something like your wetsuit, after you see how much it takes to sink it, put the stuff that sinks on it and see how much *less* weight it takes to sink it, so you'll know how much weight to take off for the stuff that sinks. Write that down too. See how much weight it takes to sink you - just you in a swimsuit - write it down. If you're diving an aluminum 80 you'll need to add two pounds to sink that when it's down to 500 psi. If you're diving some other tank, bleed that down to 500 psi (or whatever your personal end-of-dive limit is) and calculate how much it takes to sink (or float) it and write it down.
Also, on your list of stuff, write down how much each item weighs, too, including yourself. This list lives in your logbook - whenever you acquire a new piece of gear, that goes on the list too.
For fresh water, you just add up the weight it takes to sink whatever you're wearing/carrying less the weight it takes to float the stuff that sinks and use that much weight. For salt water, add up the total weight of you, your stuff and your weights and add two pounds per hundred.
Using this method, you'll be very, very close to your ideal weight every time.
Rick
Also, on your list of stuff, write down how much each item weighs, too, including yourself. This list lives in your logbook - whenever you acquire a new piece of gear, that goes on the list too.
For fresh water, you just add up the weight it takes to sink whatever you're wearing/carrying less the weight it takes to float the stuff that sinks and use that much weight. For salt water, add up the total weight of you, your stuff and your weights and add two pounds per hundred.
Using this method, you'll be very, very close to your ideal weight every time.
Rick
jobowker
Guest
The above idea sounds really good. The one thing that I'd add is to make sure that unless you're wearing it, you have to ensure that there are no air bublle trapped in your suit, otherwise they will throw off your calculations.
mlove
Contributor
I like your equation, the problem I am having is I don't have small enough increments of weights to evenly sink things.Bundeled everything together and get a pretty accurate weighting. Still seems like alot of weight.
M
M
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