Trying to put it all together

[R2K2]

I am going to dive Cold fresh water for the first time this year and wanted to learn a bit more. This forum is great resource. Here is my Dilema.

I normally dive warm salt water with an AL80, 3mm wetsuit and 17lbs of weight is perfect for me. My cold gear is a 7mm full wetsuit, 7mm vest with hood and an PST HP steel 80 (I know is in the small side)

I figure I can subtract 7lbs from my weight belt switching to Steel and subtract another 6 lbs for diving fresh water for a total reduction of 13lbs.

Would going from a 3mm shortie to 7mm full with 7mm hooded vest be an addition of about 8lbs?

So my new weight to start with would be 17 - 13 + 8 = 12lbs? seems light.
I am 6'ft 210lbs, am I missing something here?

Thanks in Advance.

 

[Garrobo]

I wouldn't spend a lot of time worrying about the weight needed. Just jump in the water with 12 pounds and see if you sink. If not, add lead till you do.

 

[OceansBlue]

Sounds a little light to me as well. With a 7mm suit and a 7mm hooded vest, I would be in the range of 10% of my body weight for fresh water. But, give the 12 lbs a shot. I knew someone in college who could sink in a 3mm suit and didn't need any weight at all. It still amazes me tody.

 

[R2K2]

I was originally thinking the same as OceansBlue about 10% body weight rule till I started reading more about it.

Would you make all your weight dropabble the first go around till you figure out the weight needed then start worrying about the 60% droppable , 40% non droppable later?

 

[Rick Inman]

I personally do not like any droppable weight - but that's for another thread.

One other thing, once you get your weighting where it feels right, after a couple more dives, I would start removing small amounts each dive until you find the real minimum weight you need. Almost everyone is a bit over-weighted at first.

I am currently making the switch to a rebreather, and last week I finally got my weight dialed in, meaning, guess what? I'm probably a bit over-weighted. Odds are after another 10 hours on the rig I'll be able to drop some weight as my technique improves.

 

[CDNScubaMoose]

I think you are going to find yourself a bit light, at least at first. Diving in the Great Lakes (I see you are from Michigan, so I am making a bit of an assumption), has some unique challenges that will be new to you - the water is darker, quite often you will be descending on a line where you can't see the bottom (assuming wreck diving here), and of course there are those lovely thermoclines. All of this is going to add to the "pucker factor" a bit and you won't be completely exhaling.

I'm also curious if your cold water suit is new or new to you. Reason being is that new neoprene tends to be a little more bouyant then that of suits that has been compressed at depth a couple dozen times.

I don't believe in overweighting but when diving in new conditions or new configuration, I usually start heavy and work my way down. I find things a bit stressful for myself if I'm fighting to hold a safety stop and if I'm fighting it then chances are I'm not completely exhaling which is making things even worse.

On the dropable/non-dropable ratio - depends on your comfort level in the water and how much weight you are talking about. For first time divers in these conditions I would likely look at a 80% dropable unless we are talking about a massive amount of lead to begin with.

Like Rick - I prefer to eventually get to a zero dropable weight situation but also like Rick ... another thread for that discussion.

Of course it goes without saying is to do your bouyancy checks in shallower conditions instead of on the first dive of a trip.