Al or SS plate

[piikki]

I am seeking more opinions on this because it confuses me. What is the right plate to get in my situation, Al or SS? I am not getting one before talking to ‘authority’ but I keep getting conflicting information on this, and am interested in hearing some reasoning.

I dive in cold water with 7mm jumpsuit or 7mm plus 4mm shorty. My tanks are Faber’s monster-heavy HP80s (about -13 full, -7 empty), I dive with singles only. My wing is Oxy SS 45lbs and this far I’ve had TransPac (+2lbs buoyant). No canisters or anything else but JetFins to add to minus side. With this combo I need 6lbs to keep my safeties.

I’ve been pushed towards choosing SS plate but looking at the weighing (and considering I am not yet at the verge of buying a drysuit), I am leaning towards Al plate because I will need a STA with my Oxy wing too. During my trial with 5lbs SS plate w/ no STA I was overweighted, using considerable amount of air at 45ft to not grind the bottom. Why would I want to overweigh myself with (minimum the loss of soft pack plus STA)? I won’t have anything left to adjust my trim with either (with stumpy tank I am slightly top-heavy). What speaks against Al plate (I was totally spoken for SS in the shop)? Is it just not DIR?

 

[jonnythan]

Al.

 

[cool_hardware52]

I am seeking more opinions on this because it confuses me. What is the right plate to get in my situation, Al or SS? I am not getting one before talking to ‘authority’ but I keep getting conflicting information on this, and am interested in hearing some reasoning.

I dive in cold water with 7mm jumpsuit or 7mm plus 4mm shorty. My tanks are Faber’s monster-heavy HP80s (about -13 full, -7 empty), I dive with singles only. My wing is Oxy SS 45lbs and this far I’ve had TransPac (+2lbs buoyant). No canisters or anything else but JetFins to add to minus side. With this combo I need 6lbs to keep my safeties.

I’ve been pushed towards choosing SS plate but looking at the weighing (and considering I am not yet at the verge of buying a drysuit), I am leaning towards Al plate because I will need a STA with my Oxy wing too. During my trial with 5lbs SS plate w/ no STA I was overweighted, using considerable amount of air at 45ft to not grind the bottom. Why would I want to overweigh myself with (minimum the loss of soft pack plus STA)? I won’t have anything left to adjust my trim with either (with stumpy tank I am slightly top-heavy). What speaks against Al plate (I was totally spoken for SS in the shop)? Is it just not DIR?

I'm not sure I follow. If you need 6 lbs with the TransPac, and assume the TransPac is +2, then with a SS plate (-5~6) and no weight you should be about 2 lbs heavy, may a little more for the STA.

I see no reason not to use a less negative plate. Loosing the Transpac saves 2 lbs, an "AL" plate will be ~2 lbs neg, STA ~1. Close to perfect, may 1-2lbs light.


Tobin

 

[Reinoud]

I am seeking more opinions on this because it confuses me. What is the right plate to get in my situation, Al or SS? I am not getting one before talking to ‘authority’ but I keep getting conflicting information on this, and am interested in hearing some reasoning.

I dive in cold water with 7mm jumpsuit or 7mm plus 4mm shorty. My tanks are Faber’s monster-heavy HP80s (about -13 full, -7 empty), I dive with singles only. My wing is Oxy SS 45lbs and this far I’ve had TransPac (+2lbs buoyant). No canisters or anything else but JetFins to add to minus side. With this combo I need 6lbs to keep my safeties.

I’ve been pushed towards choosing SS plate but looking at the weighing (and considering I am not yet at the verge of buying a drysuit), I am leaning towards Al plate because I will need a STA with my Oxy wing too. During my trial with 5lbs SS plate w/ no STA I was overweighted, using considerable amount of air at 45ft to not grind the bottom. Why would I want to overweigh myself with (minimum the loss of soft pack plus STA)? I won’t have anything left to adjust my trim with either (with stumpy tank I am slightly top-heavy). What speaks against Al plate (I was totally spoken for SS in the shop)? Is it just not DIR?

The main thing to archieve is a balanced rig. If you are overweighted with an SS backplate, you have to loose some weight. An Al backplate seems the logical choice (and cheaper that buying other tanks or something like that)

 

[Taipeidiver]

I use an aluminium plate for the simple reason that it is easier to travel with. My dive gear, complete with BP/W, cannister light, backups, jetfins, regs and all the other guff, weighs in at exactly 23kg when packed into my gear bag. It's slightly heavier on the return journey as I never seem to be able to get it all dry before flying.

I still need to wear a weight belt, albeit with only a couple of kg, but I don't mind as I am saving a fortune in excess baggage costs.

Of course, I have no idea if it's DIR or not but there will be plenty of folks here who can answer that question for you.

 

[Meng_Tze]

I dont think either 'AL' or 'SS' is specifically DIR or not. Both plates have their place and time of usage. The bottom line is to have a balanced rig. Some people achive this by using one of the two plates with or without weight belt.

I use an AL for fresh water and a SS for ocean with AL80's neither with added weights. With steel tanks I use an AL plate, when traveling I take the AL plate. I would suggest to try and see where your specific config comes in. In time the 7mm suit (I see that you dive this with steels, which is another discussion) will also loose bouyancy and you will have to get back to adjusting the rig.

If you want more ditchable weight, an AL plate is better, if your rig is more bouyant, a SS may be better. Too many variations on this theme.

 

[piikki]

I dont think either 'AL' or 'SS' is specifically DIR or not. Both plates have their place and time of usage. The bottom line is to have a balanced rig. Some people achive this by using one of the two plates with or without weight belt.

I use an AL for fresh water and a SS for ocean with AL80's neither with added weights. With steel tanks I use an AL plate, when traveling I take the AL plate. I would suggest to try and see where your specific config comes in. In time the 7mm suit (I see that you dive this with steels, which is another discussion) will also loose bouyancy and you will have to get back to adjusting the rig.

If you want more ditchable weight, an AL plate is better, if your rig is more bouyant, a SS may be better. Too many variations on this theme.

Thanks for all the input guys. I was not sure what I was missing with all the push for 'just get the SS and that's it'. I just could not see the the reasoning behind overweighing myself but I no way claim to know about these things, so I could have missed something obvious. Since I haven't been diving in tropics with AL80 yet I don't know what I will be needing but I sure would rather pack Al too.

I've heard quite enough rap about the wetsuit and steels. I know it won't end the lecture but my dives are shallow at this point, so my brand spanking new neoprene hopefully isn't going to lose all of it's spunk on me I don't think the resale market for HP80s is so great, so I might be stuck with them for awhile even though I admit I did not take my height into account when getting those stumps. Better wait for the fundies before revamping the arsenal but anyone wanting to swap them for longer bottles keep in touch

 

[lamont]

Thanks for all the input guys. I was not sure what I was missing with all the push for 'just get the SS and that's it'. I just could not see the the reasoning behind overweighing myself but I no way claim to know about these things, so I could have missed something obvious.

Well, "SS plate for single steel tanks" works as a rule for tanks that swing nearly neutral when they're empty (e.g. all of the PST E-series). You've got a tank which has that weight "built-in", so that an Al plate probably makes more sense.

I've heard quite enough rap about the wetsuit and steels.

That's with doubles. And the concern behind "don't dive wet steel doubles" is that it is difficult to obtain a balanced rig and to be able to swim up the rig with full gas and fully compressed wetsuit. If you know what you're doing these days small double steels that are neutrally buoyant at the end of the dive can probably be made to work with a wetsuit.

 

[cool_hardware52]

If you know what you're doing these days small double steels that are neutrally buoyant at the end of the dive can probably be made to work with a wetsuit.

That's the case with my faber 85's...


Tobin

 

[JimC]

If you know what you're doing these days small double steels that are neutrally buoyant at the end of the dive can probably be made to work with a wetsuit.

And this is inversely true for super heavy steel singles. There are some out there that are more negative than my double 130's, empty. Unfortunately, I think piikki's tank would probably be on the cusp of something I wouldn't dive as a single in a wetsuit. You probably don't want to be starting much more negative than -10 after your belt is off. This tank starts at -7, add in an AL plate, gear and some gas and at 100 feet you're probably somewhere around -10 after you count whats left of your wetsuit buoyancy.