Heavier plate, or P-Weight?

[kaliban]

It looks like for the forseeable future, I'm going to be using around 28-30 pounds total weight. This I've figured out using the nearly empty tank neutral buouancy check method at the end of my dive, and a knowledgeable instructor told me that I'm probably just about right on with that, though he figures I'll drop 5 pounds or so after I take the DIRF class next year sometime.

I'm considering 2 different configurations, both of which will accomodate the weight I need now, the weight I'll likely need in the next year, and the weight I might someday get down to with lots more experience. The primary differences are that the first method uses a heavier plate, which will spread the weight over my back, and the second method uses a P-weight which will put the extra weight right down my spine.

One way is to use a 12# plate, 5# STA, and where the balance on my belt (8# - 12#)

Another way is to use a 6# plate, 5# STA, 8# P-weight, and the balance on my belt (6# - 11#)

Both ways would give me the weight and flexibility I'll likely need over the next couple of years. The question I have is - Does anybody have any idea if one way is likely better than the other in terms of trim issues, etc?

thx,

-k

 

[Birdman]

The second possibility may leave you more options for getting trimmed out as you have the possibilities of using half a p-weight at the top or bottom of the plate, instead of the full p-weight. You could do the same with a 12 lb plate, but that's getting to be a lot of non-ditchable weight. I use a 6 lb plate, 4 lb p-weight on the top of the plate, and 6 lbs on a belt, a plastic dive-rite sta and a steel faber 108. When I combined a steel cylinder with a weighted sta, I didn't like the result. I presume with all that lead, you are diving in cold water.

 

[buff]

I used some Zeagle pouches attached to my backplate for extra weight.

I now know what a turtle feels like sitting upside down.

I don't know if you are going to be using the same amount of weigh that I used(I was waaayy over weighted - first time out with my new dry suit) but the "turtle effect" is something to avoid.

What about those weight harnesses by DUI or Northern Divers instead of a weight belt? I hate weight belts.

Here is another option to use less weight:

Get skinny.

It's not only good for your heart but for your ballast arrangement too!!

 

[kaliban]

Birdman once bubbled...
The second possibility may leave you more options for getting trimmed out as you have the possibilities of using half a p-weight at the top or bottom of the plate, instead of the full p-weight.

Yeah, I was wondering about that. That might make sense. The only time I've dived a plate so far I felt a bit nose down, so I might need to put some weight on the bottom side of the plate.

You could do the same with a 12 lb plate, but that's getting to be a lot of non-ditchable weight.

I don't know. The way things sit now, I only need 6-8 pounds of ditchable, I guess the rest could be all in the plate for that matter.

I use a 6 lb plate, 4 lb p-weight on the top of the plate, and 6 lbs on a belt, a plastic dive-rite sta and a steel faber 108. When I combined a steel cylinder with a weighted sta, I didn't like the result. Just out of curiousity, what didn't you like about the heavy STA approach?[/QUOTEI presume with all that lead, you are diving in cold water. [/B]

Yep, I'm diving the puget sound in a cf200. I'm 6ft and weigh 200pounds.

thanks for the info.

-k

 

[kaliban]

buff once bubbled...
Here is another option to use less weight:

Get skinny.

It's not only good for your heart but for your ballast arrangement too!!

Yeah, I tell myself that all the time I'm not exactly off the charts at 200# for 6' tall, but I could definitely drop 25 pounds or so.

-k

 

[Birdman]

kaliban once bubbled...
Just out of curiousity, what didn't you like about the heavy STA approach?

I found that there was a turtle effect, in that if you rotate sideways the moment of the cylinder began to pull me around on to my back. Personally I don't like this feeling even if I can control it as it detracts from the feeling of being weightless. Can't say that it would happen with all heavy sta's. I have a pretty heavy cylinder, too. Also, I am diving a tls350 with 200g undergarment and am 6'3", 200lbs.

 

[buff]

I never noticed a turtle effect with my 8lb plate and 5 pound sta.

but then I added the extra weight to the back and flipped over like a snapping turtle.

 

[kaliban]

Birdman once bubbled...


I found that there was a turtle effect, in that if you rotate sideways the moment of the cylinder began to pull me around on to my back. Personally I don't like this feeling even if I can control it as it detracts from the feeling of being weightless. Can't say that it would happen with all heavy sta's. I have a pretty heavy cylinder, too. Also, I am diving a tls350 with 200g undergarment and am 6'3", 200lbs.

That's interesting. In a way that makes me think about the heavier plate. I wonder if the weight was spread out over my back rather than concentrated directly under my tank, if that turtle effect might be mitigated?

It sounds like you're using about 16 pounds total. definitely less fat on your bones than I have. Also, from what I've been told, the cf200 adds about 3-4 pounds to my bouancy, and then I 'm using polortec 300 thermals, which I think is 560g, so that adds some too. I imagine after I've become substantially more skilled than I am now, I might get my weight requirement down towards 20 pounds, but that's probably about it. If that's the case, I could possible use a 12 pound plate at that point and wear 8 on my belt, though that wouldn't allow for the possability of adding some to one end of the plate or the other.

It sure is tough to know these things without actually trying them out. It's a real catch-22.

-k

 

[jplacson]

Hmmm... this is something I plan to try soon... dunno if it'll help...but you might want to try placing a couple of trim weight pockets on the shoulder strap harness (between your shoulders and the point where they meet the top of the backplate... this area doesn't touch your body) ... you can place maybe about 4# total (2# on each shoulder)

You can try the following as well:
-12#BP
-6#STA
-8# ditchable on belt
-4# on upper shoulder straps (as mentioned above) ... this may offset the heavier bottom.

Normally, trim weights are placed on the upper tank strap (that's where I have mine right now) ... but I've noticed extra sensitivity to rolling over...it's not a BIG problem... but if moving it to an area that may be better (and still not as noticable) ... why not?

If you want, you can even try using bare belt weights (ideally coated) ... 2# on each should strap... push it as far back as it can go... close to the top of the BP.

***Mind you, I've never tried this config for trim weights...not yet anyway... I was planning to do so sometime soon but be my guest to try it out... it's just for trim anyway...soft weights will probably be better though***

 

[Birdman]

kaliban once bubbled...

It sure is tough to know these things without actually trying them out. It's a real catch-22.

Therein is the rub. My m.o. is buy, try and ebay. Repeat as necessary. I have tried 4 different backplates, 2 different sta's (3 if you count sta-less), 3 different wings, 4 sets of fins and about 4-5 weighting schemes before settling on what I think works well for me. It was an evolution over about 2 years. FWIW, I think you may be on to something about the stability of the 12 lb plate. The idea I have had in the back of my head for the last few months is that the distributed mass of the 12 lb plate might bring stability, but I haven't gone there as I have something that works well. If I had to do over again I would consider the heavy Koplin plate; Koplin plates are really nicely done IMO. One correction, I actually go sta-less which helps me grab my valve, but when I did use an sta, the dive-rite was my preference.