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Shell vs. neoprene

Discussion in 'Exposure Suits' started by pnbooth, Apr 13, 2012.

  1. pnbooth

    pnbooth Angel Fish

    I've been diving my first drysuit (Diving concepts trilam) for 400 dives and its about to give up the ghost. I'm seriously considering switching to neoprene but have one big issue I hope others can help me with. The main reason I love diving my drysuit is that once properly weighted (it took me about 10 dives and needs continual adjustment with changes in gear configuration), I only use my BC on the surface. I do not want to manage two air cells. I have heard some say a neoprene drysuit can be dove the same way, but others say they can't. I'm contemplating buying a seasoft 4.5 mm (regular neoprene) so am aware that the buoyancy of the suit itself will change with depth. Anyone out there to weigh in?
  2. Gachnar

    Gachnar Angel Fish

    # of Dives: 100 - 199
    Location: Oregon
    I'm sure you'll find people with far more experience than I to answer, but I've never heard that you can't manage buoyancy with a neoprene suit. I did my AOW in my CD4 and never touched my BC underwater and had no issues. There are some downsides to managing buoyancy with just the suit (harder to dump air quickly without venting a seal, air may shift around within the suit and affect trim) but unless you are seriously overweighted it shouldn't be an issue.

    I absolutely love my drysuit, but the downsides to a neoprene suit are longer drying times, more bulk (both are more of a travel consideration than anything else) and that if you are diving deep a lot your insulation and buoyancy will go through greater changes. But they also have advantages in durability over most shell suits.
  3. scubamedics

    scubamedics Garibaldi

    # of Dives:
    Location: Angus, ON
    Hmm... I'm still not convinced why you want to switch to neoprene. The only plus side really is warmer thermal protection at the surface. You will still get quite a bit of buoyancy changes from surface to depth (albeit not as bad as on open cell 7mm). Trilam will allow you to adjust to the water temperature just by changing the thermal underwear under the suit. I've been diving with a DUI CF200 since 2002, and put over 1000 dives on it. It's on its secon zipper, and third set of seals, but it's still going strong (No leaks). I honestly don't know too many other suits that stand up like that. The TLS 450 is a pretty rugged suit as well the Santi Enduro & E-space. My current favorite is the Waterproof D7, rugged, yet flexible, and has kevlar reinforced boots. If your bound and determined on Neoprene, and you want a suit that lasts, the CF200 from DUI is the suit you're looking for. Hope this helps.
  4. Bruce Justinen

    Bruce Justinen Dive Equipment Manufacturer

    # of Dives:
    Location: Olympia, WA
    This is Bruce Justinen, President of SEASOFT SCUBA, this my take on the differences between shell suits and neoprene suits. Before anyone accuses me of being biased, I will say that I am, neoprene suits are by far a better suit than any shell suit. Shell suits only came into being in the 80s because we did not have adhesives back then that would make neoprene drysuits waterproof. Most of our neoprene drysuits were gummed up with Aquaseal.

    So here is how I see it after 28 years of drysuit diving.

    "There are a lot of "experts" out there telling people which drysuit they should buy. The problem is they are telling people based on their "experience". Usually that "experience" is based on the one or two drysuits they have owned or dove.

    It reminds me of the "pickup wars". Traditionally people are very loyal to a brand of pickup, Ford, Chevy, Dodge (now Ram), etc. Rarely, if ever, have they ever actually driven the other guys pickup but they would be sure to tell you that they would NEVER own one.
    That's often how it is with drysuits. But for the person wanting to buy a drysuit there are a lot of mixed messages, a lot of advice from divers, instructors etc. who have only used one drysuit or type of drysuit.
    I have over 5,000 drysuit dives over the last 28 years. I have experience with virtually every type of suit, vulcanized rubber, compressed neoprene, crushed neoprene, traditional neoprene, trilaminate shell, thin shell, heavy duty shell, stretched fabric over shell and hybrid neoprene suits and here is my experience with the two most widely used types.
    SHELL SUIT: In a shell suit most divers basically dive with a squeeze in order to have a useable suit (remember, the fabric doesn't stretch). Because the suit has to be cut large enough to accomodate for their movements in a non-stretchable fabric, there is excess space for air to move. This "bubble" in the suit creates potential mayhem for their buoyancy and control. So, in order to eliminate this chaos, they dive with a squeeze (they do NOT add air or they add very little, as they descend).
    Since, the diver is diving with a squeeze (no air in the suit) and since the air is what gives them warmth and since the suit itself has NO thermal protection, they are forced to wear big thick undergarments. They have NO choice.
    For buoyancy control, they must use their BC underwater, if they used their drysuit, instability would ensue for most divers.
    NEOPRENE SUIT: In a neoprene suit the diver DOES use air to keep warm. Since the suit fits like a loose wetsuit and because it stretches, the air does not form a large bubble. The air is dispersed all around the suit as a layer of air.
    When the diver adds air as they descend, more air is added to this layer. They will get a minor movement of air but it does not move as a "body" of air. The diver does not need thick undergarments because the suit itself is providing a layer of insulation but so is the layer of air AND as they add air during the dive that air continues to provide additional insulation.
    Additionally, in the winter, many divers will actually add a couple of pounds of weight so that they can add a small amount of additional air to their drysuit for additional warmth. in a neoprene drysuit ...... Air = Warmth!
    They will not use their BC for buoyancy during the dive. They will typically ONLY use their BC on the surface.
    SHELL SUIT: Once again, because shell suits do not stretch, it must be made larger, creating a large amount of excess material. This excess material creates hydro-drag. The more surface area (loose fabric, wrinkles, etc.) that water has to flow over, the more drag it produces. This uses up air, slows the diver down, tires them out prematurely - nothing good comes from hydro-drag.
    [​IMG] From Wikipedia, the larger the surface area presented to the water, the more hydro-drag produced.
    NEOPRENE SUIT: Since neoprene stretches, it makes for a closer fitting drysuit and presents far less surface area to the water, typically 20-30% less fabric.. Thus, there is less hydro-drag (less resistance) in a neoprene drysuit and it is not uncommon for divers to have longer bottom times with part of that reason being that they are also warmer.
    SHELL SUITS: So often, even with the thicker undergarment many divers are cold when they dive their shell drysuits. Of course, part of the reason is because they are diving in a squeeze (no air in the suit). This causes the suit to collapse in on the undergarment and forces it against the body. This can potentially eliminate a significant amount of its thermal protection. Also, the suit itself has NO thermal protection and with no layer of air, the only thermal protection is the undergarment.
    NEOPRENE SUITS: Neoprene suits possess three separate means of providing thermal protection.
    1. A layer of thermal protection in the air bubbles within the neoprene itself.
    2. The layer of air around your body that you can add to via the intake valve located on the chest.
    3. The undergarment is a layer of thermal protection. Three will always beat one.
    There are arguments made by some that you need more weight for a neoprene drysuit. The answer is yes you do!
    If you were diving a shell suit with a squeeze then yes, diving warm, comfortable and longer in a neoprene drysuit will require more weight but that is like saying that steel tanks costs more than aluminum. Well, yes, they do but the advantages are worth it. In the case of neoprene vs shell, as amazing as it is, the neoprene is usually the less expensive of the two.

    So there you have it, neoprene suits are warmer, have less drag, you usually have a longer bottom time, you swim faster using less energy and cover more ground, you are less fatigued, they are way more comfortable and they cost less. If that doesn't make sense well, then go drink more kool-aid.

    The biggest problem neoprene drysuits face is the shell drysuit owners who don't know what they are missing and are too afraid to admit that they are paying more money to get less suit. But hey, that is just my opinion after diving all the suits over 5,000 dives over 28 years.

    Thanks for listening to my opinion, you are certainly welcome to your own.


    manni-yunk likes this.
  5. Tigerman

    Tigerman Solo Diver

    # of Dives: I just don't log dives
    Location: Norway
    Id like to add something to that..
    The neoprene suits tend to be a bit more cumbersome when on land as they are stiffer and heavier, in other words a bit more tricky to handle on land.
    They can also be a bit on the warm side depending on the location you dive.

    Personally Ive always been using only the suit for bouyancy both the dives I had testing shell suits and with the crushed neoprene suit I ended up buying and its no problem doing so as long as youre properly weighted.
  6. Bruce Justinen

    Bruce Justinen Dive Equipment Manufacturer

    # of Dives:
    Location: Olympia, WA
    Actually, SEASOFT makes 3, 4 and 4.5 mm neoprene drysuits and our 4 mm XV-4 is so incredibly flexible that you feel like it is maybe 1 mm thick. There are other manufacturers who are following our lead and going with thinner, lighter neoprene drysuits.

    Things have changed from the days of the 6 and 7 mm thick, stiff neoprene suits. Todays suits run from compressed, semi-compressed to super-stretch.

    The problem with crushed neoprene is that you have lost all the advantages of neoprene - the air is gone so you have lost the thermal protection. Virtually all of the stretch is gone, so you end up with a very heavy shell suit really. It's only redeeming quality is that it is extremely tough. But there are a lot more reasons to buy a drysuit - like comfort, warmth, stretchiness and freedom of movement.
  7. PfcAJ

    PfcAJ Orca

    # of Dives:
    Location: St Petersburg, Fl
    Bruce, I dive a shell suit. I add air all the time. Lots of it. If you're diving with a squeeze, you're doin' it wrong. You've got to loft the undergarment. If you're trying to be slick and keep a tight squeeze, all thats going to happen is you're going to shiver your butt off on the long dives.

    One thing I'd take a long, hard look at when deciding on a suit is where the zipper is in relation to your BC/ harness straps. The LAST place I want a zipper is where the harness is rubbing on it and where you can't unzip it quickly on an unconscious diver.
  8. tracydr

    tracydr Divemaster

    # of Dives: 500 - 999
    Location: North Carolina, 3 miles from South Carolina
    I'm surprised, with 400 dives, that your DC drysuit needs replacing.
    What's wrong with it? I have a new one, which I just started diving. My husband has one which is about 12 years old and has about 1,000 dives. He's had the seals changes and I think the boots/ knee patches replaced.
  9. Tigerman

    Tigerman Solo Diver

    # of Dives: I just don't log dives
    Location: Norway
    Im not surprised.. By the start of every season (the waters frozen over 4-6 months each year locally), my drysuit has shrunk while in the closet..
  10. Ordie

    Ordie Instructor, Scuba

    # of Dives: 200 - 499
    Location: North East Texas
    Bruce is correct in saying that most dry suit divers have tried and used one or two suits. The problems Bruce describes above concerning shell suits are due to divers not using the suit correctly. I have tried neoprene, vulcanized rubber, and shell suits. I have used all of these from different manufacturers. Neoprene suits are cumbersome and require a lot more weight. Neoprene suits will lose insulating properties at depth due to compression. Neoprene suits are cheaper cost wise for a reason. I have used a DUI CF 200XL since 2000. I have changed the seals one time. My CF200XL has seen cold water in Washington state where I originally began using it, it has been in the lakes of Texas, and in the Sea of Cortez. I have never experienced air bubbles inside the suit. I do not dive with a suit squeeze. Also I do not use my suit for buoyancy, that is what my BCD is for. Shell suits are more expensive because they are designed and made better. No offense to Bruce, but Seasoft wraps everything in neoprene including weights. Which suit you use comes down to comfort and your ability to use the suit properly.

    Thats my opinion

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