Dry Suit Diving

Maria Maggio has worked with DUI since 1996 on a variety of projects including teaching the DUI-sponsored seminar "How to Teach All Levels of Training in Drysuits" at DEMA and other shows. Maria also regularly participates in DOG events and works with dry suit divers and instructors to better refine their diving and teaching of dry suits.

What follows are some suggestions on a number of dry suit related subjects which Maria has found useful. This information is not a substitute for proper dry suit or dry suit instructor training. Maria Maggio and AquaMarine Divers accept no responsibility for errors, omissions, or inaccuracy of these suggestions. Use at your own risk.

Teaching All Levels of Training in Dry Suits and in particular Entry Level

I've found in 10 years of teaching that students stop learning as soon as they are cold or have to go the bathroom. I can't help with the bathroom part, but as for being cold, for all of us diving in the 35-85 degree temperature range, there really is no need to be cold. Some people worry about task overloading by teaching in dry suits, especially at the entry level. Some of this stems from the myths and misconceptions about dry suit diving. It really did use to be harder to dive in a dry suit. Suits weren't made of as good materials and often didn't fit most people very well (especially women). Things like crotch straps and telescoping torsos didn't exist, so there often was a lot of drag. Boots were poorly fitted for a lot of people making kicking difficult. Today with modern dry suits (and yes, I freely admit, I am 100% biased towards DUI suits), diving in a dry suit is no harder than diving in a wet suit. And, if it makes you warm, it's easier. The success or failure of our students to learn how to dive in a dry suit is much more a factor of how we teach it than anything else. We have our students' best interest at heart and don't want them to get hurt, so we discourage them from trying out dry suits without proper training. But, what we tell them is dry suits are hard to use, and they need special training, and are very dangerous. The student walks away thinking, "I'm never using one of those things." But, a regulator for someone who doesn't know what it is and how to use can be difficult to use. It certainly can be dangerous if used improperly. And, there's no doubt you need special training to use a regulator. Can you imagine opening your Open Water SCUBA class on the first night and showing a regulator and explaining it like that? No, what we do is show the regulator and say that we're going to show you how to use it properly and safely. I think we should be doing the same thing with a dry suit. I know at least in our area (New England), there are people who will never dive warm and comfortable unless they are in a dry suit. A dry suit is as essential a piece of equipment to these people as is a regulator, BCD, and mask.

Divewear

Many times people will spend the money for an expensive dry suit, but then use ski or other fleece materials or worse "sweats" under a dry suit. Cotton should never be used under dry suits. This is for the same reason that hikers or other outdoor activists reject cotton. Once cotton has gotten wet (either from perspiration or from leaks), it loses most of its insulation ability. Another alternative that some people use is generic fleece material. Good dive insulation is very warm for its volume and is more resistant to compression. Remember that as our volume increases, so does our buoyancy. This means a diver will need to wear more lead weight to be properly weighted. So, if you are a dry suit diver, make the investment in good divewear. If you are a dry suit instructor, encourage your students to wear proper divewear. If you are a store owner, if you've made the investment in rental suits, also make sure to include good divewear as well. Otherwise, when your students and customers rent your dry suit and are either cold or need to wear excessive weight, they will not fully appreciate the benefits of dry suit diving.

Underwater Weighting Check

Most people are aware of the standard method to check for proper weighting. If you are in water just over your head and deflate your BCD and dry suit, then holding a normal breath, you should float at eye level. When you exhale slowly, you should start to sink slowly. If you do this at the beginning of a dive with a full tank, you should add 5-6 pounds to compensate for the weight of the air in your tank. When diving with dry suit, a second method is also useful. During the dive (perhaps at the end when your tank is nearly empty), make sure that you are neutrally buoyant. Get into a vertical position and raise you right arm. This will cause all of the air in the suit to form a "bubble" and rise to the highest point. (Don't raise you left since this will tend to allow air to vent from the suit.) If you are properly weighted, the air bubble will be small enough to fit between your wrist seal and your elbow. If the air bubble is larger than that, you may be wearing too much weight. Again, this check works best when you have a near empty tank. If you have a full tank, the air bubble will tend to be slightly larger.

Fitting Neck or Wrist Seals for Dry Suit Students

One common question that comes up with rental suits or dry suit students is fitting the seals for the neck or wrist. Wrist seals are generally easier to fit. If the seals are too tight, trim them back. If they are too loose, often all you need to do is pull the seal further back on the forearm. The arm gets wider as you move away from the wrist, so this will often work fine, as gloves will cover part of the forearm anyhow. Neck seals are usually more difficult. If a neck seal is too tight, either trim or use another suit for this student or customer. If the seal is too loose, one option is to use neoprene "helpers." There are neoprene strips that can be worn around the neck. The latex neck seal then sits on top of the neoprene strip. It's best if you can find a suit with a neck seal that fits, but if not or you're in a pinch, these "helpers" can save the day.

Deflator Value Position - Open or Closed?

I almost always dive with the deflator valve opened all the way and teach my students to do the same. If I need to vent quickly, all I need to do is get into a vertical position, tilt slightly to the right, raise my left upper arm, and lower my left lower arm. If divers want to close back their valves, it often means they are diving with too much air in their suit, which often means they are wearing too much weight. The one exception I've encountered was on a trip to British Columbia while I was diving in the high current Browning Wall. As I would stop to take a picture of the abundant life growing on the wall, I would raise both arms and look through the viewfinder. As I raised my left arm, I would accidentally vent air out of my suit. For this fairly unusual case, I turned down my deflator value just a few clicks. If you do this, it's very important to remember to open it back up before starting your ascent. But, for most recreational diving, normal body position is horizontal, so consider diving with your deflator valve opened all the way.

Body position During Ascents

One thing I really try to stress with my dry suit students in proper body position during ascents. If you are diving in a dry suit, it's a good idea to get in a vertical position and hold onto the low pressure inflator to prepare for the ascent. This allows the student to have possession of the LPI so when he or she hits the surface he/she can get positively buoyant easily without having to search for the inflator. I stress that the student should be tilted slightly to the right, with the left upper arm horizontal to the bottom. The forearm should be facing down, and not up as in an ascent diving without a dry suit to prevent air from being trapped between the deflator valve and the wrist seal. Experienced divers will often have their upper body is a good position, but will be sloppy about their leg positioning, as leg position doesn't really impact venting from a BCD. But, it certainly impacts venting from a dry suit. Have your students practice body position for ascents in the pool. Most pools aren't very deep, so they can't do much of an ascent. But, if you get them in the habit of proper body position, the ascents will be much easier in open water.

BCD use while diving with a Dry Suit

There are few absolutes in diving (or life), but I think you should ALWAYS use a BCD even with diving with a dry suit. The main reason in my opinion is that the BCD is necessary to achieve positive buoyancy on the surface. Adding enough air to the dry suit would be very uncomfortable and potentially dangerous as the excess air would tend to put pressure on the neck. An important secondary reason is in case of dry suit failure under water and lost buoyancy control, the BCD would allow you to regain buoyancy control under water while you aborted the dive. With that said, there is a lot of controversy about whether to use both the dry suit and the BCD underwater for buoyancy control. Here are my recommendations, but again, your mileage may vary. For beginning divers or beginning dry suit divers, I recommend only wearing recreational dive gear and carrying recreational dive equipment. The typical recreational diver wearing recreational equipment should wear sufficient weight to be neutral at the surface with no air in the BCD and enough air in the dry suit to keep the dry suit underwear lofted (not compressed). During the dive, as the diver descends and air in the suit is compressed, the diver should add air to keep the divewear continually lofted. If the diver starts the dive neutral (or close to neutral) and keeps the divewear lofted throughout the dive, the volume of the diver will remain constant which means the diver's buoyancy will stay constant. This means there would be no need for the diver to add air to the BCD. As a beginning diver or beginning dry suit diver, it is easier to learn with only having to manage a single air space. The exception comes in with foam neoprene suits taken to depth, which is why I recommend that new divers or new dry suit divers do not use foam neoprene suits except on shallow dives. This is because when a foam neoprene suit is taken to depth, it loses considerable buoyancy. The two options are to add air to the BCD which can be complicated for a diver just learning or add more than a small amount of air to the suit which can make dry suit diving difficult or even potentially dangerous. With experienced divers, there very well may be cases where it makes sense to add air to both the dry suit and BCD. An example of this is cave diving in fresh water with cave lights, multiple reels, double tanks (often low-pressure steel), etc. In this case, often divers are very negatively buoyant. Adding so much extra air to the dry suit would likely cause excess drag and is potentially dangerous. In a case such as this, it may very well make more sense to add air just enough air to the dry suit to keep the divewear lofted, but then add enough air to the BCD to get neutrally buoyant. The assumption would be that someone who is participating in such a diving activity would be sufficiently trained and experienced to handle the complexity of managing two air spaces.

After Diving Maintenance

If you dive in salt water and/or sandy conditions, I suggest that you rinse your dry suit zipper before you even unzip it from the dive. All you need to do is carry a small jug of fresh water with your dive gear. Before you unzip, run a small amount of fresh water over the zipper. This will help reduce damage to the zipper caused by unzipping with salt, sand, or other contaminants on the teeth of the zipper.

Special offer for DUI Dealers: Maria will travel to your facility and conduct the "How to Teach All Levels of Training in Drysuits" for your staff (minimum of 5). The training itself is free, and you will only be charged for travel expenses. Please call for more information or to make arrangements.