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rubberduck
08-14-2007, 13:12
I recently purchased a new steel HP100 after doing my 1st 100 dives with AL80's. I removed 6 lbs for the 1st couple of dives and will probably remove 4lbs more on the next dive this weekend.

My problem is when I turn sideways (swim on my side). I feel the weight of the tank want to turn me around (upside down).

Anyone have similiar problems switchuing from aluminum to steel? I think I still may be overweighted.

skdvr
08-14-2007, 13:19
I had the same problem, but I switched from al 80's to HP 130. When the 130 is full it is heavy and I have to roll slowly. You just have to remember that the steel tank will be much more neg so when you start to rotate the tank is no longer trying to push you down, it is just trying to sink to the bottom. You just have to roll slow until you get use to it. It will be tough when it gets past your center of gravity though.

Just my .02

Phil

cummings66
08-14-2007, 22:11
I think any tank will eventually pull you around if it's heavy enough. To be honest I don't notice it with mine but then I don't go motionless on my side. I'm sure if I did I would roll, but if I'm moving forwards it's never an issue.

Coaster
08-14-2007, 23:19
I recently purchased a new steel HP100 after doing my 1st 100 dives with AL80's. I removed 6 lbs for the 1st couple of dives and will probably remove 4lbs more on the next dive this weekend.

My problem is when I turn sideways (swim on my side). I feel the weight of the tank want to turn me around (upside down).

Anyone have similiar problems switchuing from aluminum to steel? I think I still may be overweighted.

I removed more weight than that and needed to adjust/tighten my BC straps (and my tank strap placement slightly). Are you diving a wetsuit?

rubberduck
08-15-2007, 06:37
I recently purchased a new steel HP100 after doing my 1st 100 dives with AL80's. I removed 6 lbs for the 1st couple of dives and will probably remove 4lbs more on the next dive this weekend.

My problem is when I turn sideways (swim on my side). I feel the weight of the tank want to turn me around (upside down).

Anyone have similiar problems switchuing from aluminum to steel? I think I still may be overweighted.

I removed more weight than that and needed to adjust/tighten my BC straps (and my tank strap placement slightly). Are you diving a wetsuit?


Yes I'm diving wet with a 2 pic 7mil suit. I'm going to remove 4 more pounds this weekend and see hoe it goes.

DougNR
08-15-2007, 07:08
My problem is when I turn sideways (swim on my side). I feel the weight of the tank want to turn me around (upside down).

Anyone have similiar problems switchuing from aluminum to steel? I think I still may be overweighted.

I have a question, but I don't want this to look like a BP/W rant...

Those of you agreeing with the rolling affect caused by the added weight of the steel cylinder, are you using jacket style BCD? Off the top of my head, added weight on the back combined with the majority of your buoyancy to the front could sure add to the problem. If you still need to shed a few pounds of lead that could make the flipping affect even worse.

I dive a Zeagle back inflate unit and have not experienced the issue when I use steel. I own Alum 80's but occasionally use a steel 100. This is probably about the weight of the tank and the buoyance of the wing having similar centers that ballance as opposed to offset weight vs buoyancy that tend to flip you on your back.

I enjoyed your post, it was interresting!

BSea
08-15-2007, 08:15
Are you diving any weight at all after you take off the extra 4? Are you using a weightbelt? If you can move any remaining weight more to your front, you might counteract the roll you are experiencing. I think DougNR may have hit it on the head if you are using a jacket BC. If you have to add air to your BC, and it's a jacket, it might actually be causing more of a roll because the air in the bladder might be on your sides as well as the back. And maybe the front as well since you seem to be overweighted. With a back mounted bladder, the air would tend to counteract the roll since none of it is in front or on the sides.

But I dive a BP/W also, so I don't experience the roll you describe.

rubberduck
08-15-2007, 09:57
Yes I have a jacket BC. After the 4lbs comes off I'll still have 24lbs on my weight belt. The weight that I dropped all came out of the BC.

BSea
08-15-2007, 10:40
Yes I have a jacket BC. After the 4lbs comes off I'll still have 24lbs on my weight belt. The weight that I dropped all came out of the BC.
Do you put much air in your BC when you dive? That seems like a lot of weight even with a 7mm FJ. But everyone is different, and if you are diving salt water, then I could see where 24 lbs isn't out of the question. Especially with a jacket BC which is very bouyant to begin with.

I think if you play with the placement fo your weights, you'll be able to have a more stable setup. It will probably take a few more dives for you to get dialed in.

(Now for the traditional BP/W speal) Seriously, if you want to get rid of more of that lead, you should try a BP/W. I'll bet that 24 will drop to about 12 if you do. I'm not saying you should switch, just try it if you can. I think whatever makes someone comfortable in the water, works for them, and is what they like is what they should dive. I happen to like my BP/W, but I've got buddies that have more experienced than I have, and more training than I have, that won't give up their BC of choice.

cummings66
08-15-2007, 14:37
[quote=rubberduck;24825]Those of you agreeing with the rolling affect caused by the added weight of the steel cylinder, are you using jacket style BCD?

I was not exactly agreeing with it, but I can see how it happens. Consider my typical stop where I'm at 20 feet not moving a muscle. If I lower my legs my trim goes feet down, if I raise them higher my trim will go feet up. I'm neutral in a certain position and any change from that position will change my trim. Trim also would affect face up or face down. You can balance a tank either way, but if you go sideways gravity MUST take affect. That's how the center of gravity works, it's top to bottom, side to side. You have a certain point where things balance and only there will you not move. Go outside of that range and you must then move.

What we're talking here is the same thing. In effect there IS weight above your back, if you swim on your side and stop trying to rest on your side logically you MUST rotate tank down, it is the heaviest thing there and you do have more weight there. It's not much, and it should be a slow effect that occurs, not a rapid flip.

I've never tried this, I have never found a need to become motionless on my side, but I will bet you if I did and I did not move a muscle then I would rotate. I bet most divers would.

I dive a BP/W by the way, any my trim is as close to perfect as I can make it. I can change my movement by moving my arms or legs while I'm motionless. When I say motionless I mean not even my eyelids twitch. That's how still I am. In that state I believe I would rotate slowly if I was on my side.

cummings66
08-15-2007, 14:47
But I dive a BP/W also, so I don't experience the roll you describe.

This is what I don't understand, but let me say I've never been rolled even when sideways. I think that's because I don't go motionless or stay there long enough when I do.

Even on a BP/W setup, when you turn sideways the air in the wing will still go upwards, top side of the tank in other words.

Hey I think I figured it out. The air will go high and because it's high it will have more effect than the few lbs of steel weight and thus will pull you sideways towards the air trapped up high. It should self stabilize with you on the side, exactly 90 degree's. If you was at 45 degree's you should rotate to 90 degree's and stop, maybe have a small oscillation before that occurs.

At any rate as I said before I've never been rotated, but I think you should be able to experience it slightly based on my comments right above, stopping at a 90 point with 360 and 180 being flat on the top and bottom. 90 and 270 being sideways.

skdvr
08-15-2007, 16:23
Go out and give it a shot this weekend Matt and let us know what happens. I would try it but my BP/W is not quite adjusted correctly so who knows how messes up my results would be. I would be interested to hear what happens though.

Phil

lucidblue
08-15-2007, 18:58
I had to drop about 10 lbs when I used a steel HP100. Might have even been able to drop 12, but didn't get to try it.

cummings66
08-15-2007, 22:11
Go out and give it a shot this weekend Matt and let us know what happens.

If I get to dive this weekend, and you can bet I'm going to try I promise to test my theory.

I know that I've have tested my trim in all directions and can make myself rotate in any direction by moving my hands or legs, but I've never thought to do it sideways. I mean who or why would you want to remain sideways? I am curious about it though and I now think you should be able to stay sideways with no effort, with a wing.

Don't get me wrong, my buoyancy/trim is not where I want it yet, but it's so close I can taste it. I'm searching for perfection and someday I might be lucky to get close. Lot of distance to go. However I think this test is easy enough to do.

Storms are called for this weekend so I am not certain I'll get to try it out, but if I can I will, and if somebody else does it first report back what happened.

The test conditions are this. You must turn sideways, 90 degree's, and without moving a muscle maintain buoyancy and trim for at least 1 minute. Note what happens to your body during this period of no motion and report the results. It'd be nice to have it in a jacket BC and a BP/W.

Coaster
08-15-2007, 22:37
Yes I'm diving wet with a 2 pic 7mil suit. I'm going to remove 4 more pounds this weekend and see hoe it goes.[/quote]


I dive a 7 mil with a hood and 5mil gloves. Keeping alot of weights in my BC wasn't great so I used a belt which I didn't like because it slipped out of position.

I got a DUI harne$$ and weight management became easier for me and I like the setup for contingency weight dropping.

24 pounds works for me at the lake.

rubberduck
08-16-2007, 09:04
I'm going to give 24 puonds a shot this weekend and see if it helps any.

Thansk for all the good info

jerdr1
08-19-2007, 08:43
I found to avoid the roll I just raised my tank higher on my bc. Not sure if it would work for everyone but it did for me..

Hollywood703
08-19-2007, 15:39
another question do you always seem to roll the same way? If not it is more likely the way you swim and the new added weight. If you constantly roll to one side then you need to use trim weight on the opposite side to help offset this, if you roll both ways, more than likely when you swim your back is twisting a bit and the tank roll is taking over.

cgvmer
08-19-2007, 21:11
I don't feel the tank swing when I roll with my bp/w ..but I don't travel with any air in my wing.

Hollywood703
08-22-2007, 11:03
I agree that if you are using a jacket style BC, your center of roll is almost the dead center of your body.....with a wing or rear inflate, the center of roll is the center of the wing. Its like this...with a jacket.....you have a round piece of wood......with a another heavier piece of round wood on top....unless perfectly balanced....it will want to tip one way or another. with the wing...its more like piece of flat wood with the heavier round on top...if it gets rolling it will tip over, but the air is more long and flat compared with a more circular pattern with a jacket style. hope that gives you a beter visual.

Jamesmb
08-22-2007, 18:05
I was just reading this thread and recently experienced for the first time this problem when I started using a too big for me Zeagle BC. It would roll me so what I did was really tighten up the straps at depth and that seemed to settle down. The first dive I had with the BC and my steel 120 was going to the right. On the next dives that went away. Before this I used a Tusa Imprex and had no troubles at all.

ScubaLover
08-22-2007, 21:09
I recently purchased a new steel HP100 after doing my 1st 100 dives with AL80's. I removed 6 lbs for the 1st couple of dives and will probably remove 4lbs more on the next dive this weekend.

My problem is when I turn sideways (swim on my side). I feel the weight of the tank want to turn me around (upside down).

Anyone have similiar problems switchuing from aluminum to steel? I think I still may be overweighted.

I too went from an AL80 to a steel 100, but I use a parachute style BCD with mine. I went with the 100 for its height and considering getting a 130 as well.

It took me a couple dives to get used to it, but I have no issues with it now. When I was using the AL80 I tested buoyancye in the pool and knew how much more I'd have to use for salt water. So, when I got the 100 I dropped 2 pounds and then 4 more. I kept writing the weight in my dive log to see what worked and what didn't.

I would suggest that you take a trip to a shallow spot and keep testing the buoyancy until you get it right. I have a friend that just got a HP130 and this is what she did on one afternoon.

Good luck!

Theepdinker
08-25-2007, 12:51
[quote=rubberduck;24825]I use a parachute style BCD.
Explain please. I have no idea what you mean.

Theep