Aluminium or steel backplate for my setup?

[SailfishX]

Hi!

Which equipment combination is best?
1. 7mm wetsuit + ECS 2x8.5litre 232bar SS twinset + Halcyon Evolve 40lbs wing + Halcyon SS backplate
2. 7mm wetsuit + ECS 2x8.5litre 232bar SS twinset + Halcyon Evolve 40lbs wing + Halcyon Alu backplate

Yeah, I know it has been many threads on here about steel vs. aluminium backplates, but none of them have really given me good answers to what I'm wondering about in my case.

I come from Norway, but study medicine in Poland. Because of this I won't get an opportunity to scuba dive in Norway outside the summer holidays, for 5 more years. That is why I only use a 7mm wetsuit for scuba diving in Norway.

 

[Doc Harry]

If you are not going to be flying with your gear, and therefore not limited by weight, then a steel backplate would be more useful.

I have an aluminum backplate for travel.

 

[SailfishX]

If you are not going to be flying with your gear, and therefore not limited by weight, then a steel backplate would be more useful.

I have an aluminum backplate for travel.

So there will be enough buoyancy in the 7mm wetsuit, at let's say 90 feet, so that if I release all the drop able weights in an emergency I can easily swim this rig up, even with a non-functioning wing?

 

[redacted]

So there will be enough buoyancy in the 7mm wetsuit, at let's say 90 feet, so that if I release all the drop able weights in an emergency I can easily swim this rig up, even with a non-functioning wing?

With a 7mm wetsuit at 90 ft, if you release ALL of your weight you will likely have another emergency.

I can not imaging what could possibly make an extra 4 pounds in a BP a bad thing with a 7mm wetsuit.

 

[SailfishX]

With a 7mm wetsuit at 90 ft, if you release ALL of your weight you will likely have another emergency.

I can not imaging what could possibly make an extra 4 pounds in a BP a bad thing with a 7mm wetsuit.

Haha, yeah but that is a good thing! That means that I will still be able to carry drop able weights for safety even with the SS backplate.

By the way, what do you think has most buoyancy, a 7mm wetsuit or a drysuit with only enough gas to be comfortable?

 

[chrpai]

I can not imaging what could possibly make an extra 4 pounds in a BP a bad thing with a 7mm wetsuit.

Did he mentions what kind and how many tanks he dives and how much he currently wears on his belt? Otherwise your point is very valid.

Taking it from the other direction, I wonder if AL plates serve much of a purpose anymore. If I had to choose between an ABS plate like on the Zeagle Express Tech, an AL or a Steel, I see the benefit of the ABS and the Steel with regard to weight off your belt or weight off your suitcase, but the AL just seems kind of a minor "just a little weight" off my belt.

Hopefully that makes sense. If taking webbing on and off wasn't an anonyance, it almost might make sense for a group of divers to share a lighter plate for when someone goes on a trip.

 

[redacted]

Haha, yeah but that is a good thing! That means that I will still be able to carry drop able weights for safety even with the SS backplate.

By the way, what do you think has most buoyancy, a 7mm wetsuit or a drysuit with only enough gas to be comfortable?

I am a WWW (warm water wuss) and have never dove either. But a friend of mine had a 7mm for a short time that was 30 lb buoyant. I have to believe the dry suit, in the same temps, is not as bad.

BTW, I can't imagine trying to do cold water and tropics with the same BP/W, primarily from a travel weight standpoint. My "cold" water setup (15C) is a 6 pound plate (6mm Al) and my tropics setup Is an ultra light plate that comes in around 1 pound including webbing.

I have a couple aluminum plates but that was what I found in the pile of scrap metal that my tools could handle.

 

[decompression]

I have to agree, a 7mil wetsuit's buoyancy at deeper depths is not exactly "desirable". If there is any kind of a wing failure it would make a swim to the surface (or performing min deco stops) very difficult. A balanced rig is very hard to achieve with a thicker wetsuit at dept. So, if your only option is to perform a positive ascent then have as many options for ditchable weight as possible and go with a lighter plate. But maybe have a good look for a drysuit and see what you can find.

 

[Jim Lapenta]

I have steel and aluminum plates. The al plate is on my travel set up and I'm setting another up for student use for Intro to Tech training with small doubles. With a dry suit I use a steel plate with double tanks and maybe 6 extra pounds on a belt depending which set of doubles I use. For drysuit and single tank I use a steel plate with 8lbs of weight bolted to the back-plate. And depending on whether it's a single al80 or steel lp95 I will add a weight belt. Never been in a 7mm suit. When it came time to consider cold water diving my size dictated that a good fitting 7mm would need to be a full custom. Cost was less than a drysuit but not enough to offset the benefits of diving dry, including the overall long term costs. 7mm full custom at the time was around $800, Drysuit with undergarments $1500. Life of the drysuit for me 6 years and 200 dives until I sold it to the second owner who has a hundred or so dives on it with little maintenance. 7mm I might have gotten 5 years out of it and would not have been able to use it on many of the dry dives I did. Resale value - effectively zilch.

I do use more weight with my new drysuit but I'm also using a different undergarment and still working things out. I may have to get down to the shop and just try a 7mm and get myself weighted just for comparison. But I can't see switching. My GF dived a 7mm everywhere as she gets cold easily. Got her a drysuit and weighting so far is the same, it's warmer, packs up smaller (shell suit), and is easier to get in and out of.

 

[doctormike]

BTW, I can't imagine trying to do cold water and tropics with the same BP/W, primarily from a travel weight standpoint. My "cold" water setup (15C) is a 6 pound plate (6mm Al) and my tropics setup Is an ultra light plate that comes in around 1 pound including webbing.

I don't know the buoyancy characteristics of that twinset to comment on the specifics of the OP's question, but I have a steel Halcyon backplate. I take it to the Caribbean with my Eclipse 30 lb wing, and it's great to not need any weight on a belt or pockets. I use it with an evolve 60 lb wing with my manifolded 119s and my dry suit at home in NYC, again no additional weight needed. Yes, it's an extra six lbs in my luggage, but I really like having my rig set up exactly as I like it wherever I go.

Finally, a good used dry suit doesn't need to be a lot more than than a 7 mm wetsuit. It would be much more comfortable, and would give you redundant buoyancy in case of wing failure. I would consider that option. Dry suit buoyancy depends a lot on what you wear underneath it...