Sunday, August 2, 2009

Diving Inside Scuba dry suits

Even for the experienced divers the use of scuba dry suits means learning to dive again. There are many places where you can take a course to understand well what is a dry suit and how to use it. Let's understand the concept of this type of suit: they are air receptacles. This translates into some trouble when you try to control your buoyancy. The first consequence you can face is that being airspaces, scuba dry suits get compressed as pressure gets higher. The compression will make folds, squeeze and pinch. To prevent that, you simply need to let some air in the suit through the chest valve as you descend.

As you dive you can easily loose track of basic security precautions. Imagine for example, a situation in which you get distracted because something gets your attention in the bottom and you go for it head down. All the air in the dry suit will go them to your feet (your highest point)and expand as the pressure there is smaller. So, you are suddenly pulled up and struggling to regain control of your buoyancy. This quick ascend can be very dangerous as you can get the decompression sickness (DCS). Don't panic! What you need to do is to bring air to the upper part of your body so you can release the excess of it through the valve in your arm. In order to do so, the trick is to roll yourself into a ball and them turn till your head is up.

Scuba dry suits are great tools to make you have great diving experience, like sub aquatic photography or exploring shipwrecks. but make sure that you are well trained before getting inside one.

Monday, July 27, 2009

How to use Scuba dry suits

In the video below, you can get a very good overview of how to use a scuba dry suit.
What are scuba dry suits

Tuesday, June 30, 2009

Diving women

Diving for women.

There are two issues affecting women that could also affect their diving experiences or their bodies: menstruation and pregnancy.

Some women are worried that diving during menstruation can be dangerous. There are two main concerns: what happens when diving is in waters were there could be sharks and if it is safe to use tampons.

About the first one, we have to say that the amount of blood that can be in the water will be really small and composed in its greater part by dead cells. Sharks are attracted mainly to fresh blood so there’s none or little change that a menstruating woman will have a problem about it. Indeed, regarding sharks, shiny jewelry and fashionable suits with contrasting colors (something that most women love) can be much more dangerous. Such a things can be taken as fish scales by sharks and then they may attack a lonely diver.

Over the second concern, there is no evidence that tampons will cause any effects due to the increasing pressure while diving: as the vagina is not a closed space, it is not affected by Boyle’s law.

However, what it is important to take into consideration when diving during menstruation, is that the risk of dehydration is higher so it is necessary to drink bigger amounts of water to prevent it. Also if you have a heavy flow and or anemia, you may want to wait till it’s over for diving as these circumstances reduce already the circulation of Oxygen in the blood.

Another aspect that we should highlight for women is pregnancy. No doctor recommends diving while pregnant as the amount of nitrogen in the blood can affect the fetus (that will receive less supply of oxygen). It is only safe to do so in the first 2 to 4 weeks.

Monday, June 29, 2009

Dive Skin

With water taking away your body heat 25 times faster than air which can cause hypothermia, it is very important for the diver to choose the appropriate suit to keep the warmth inside.
Only on the warmest of the water (like the Caribbean) it is recommended to wear the lightest of all suits: the dive skin. It is mostly made of Lycra and will prevent cuts, scrapes, abrasion or stings while diving.The dive skin offers almost no thermal protection, so if you are planning to do more than one immersion per day it is better to use a wet suit.

Another use of the dive skin is to be wore under the wet suit. In the past, divers used to wear panty hoses with the same purpose: make the wet suit easier to put in and out as the neoprene slides better over Lycra than over human skin.

Maintenance of the dive skin

As with any other dive suit, the main point is to keep the dive skin always clean and dry.
After each dive there would always be salt or dirt residues in your dive skin. The dive skin should be rinsed inmediately after the dive in clean, fresh water. Make sure is completely dry before storage it so you can prevent damage, odor and mold or mildew. It is also possible and adviceable to hand or machine wash with a mild detergent regulary.
Never use a dryer on it. Let it hang out of the sun (as it can damage the Lycra) in a wide hanger.

Thursday, June 25, 2009

Scuba Dry Suit

In this post, I will explain what is a dry suit, its types and a couple of tips on how to maintain it.

As water takes away your body heat 25 times faster than air, it is crucial to choose the appropriate thermal protection when diving. Several dives in a wet suit in colder water than 65ºF/20ºC will diminish your abilities and efficiency seriously. Under 55ºF/16ºC a scuba dry suit is essential.
The main function of dry scuba suits is to keep the diver dry: the suit has several seals that prevent the water from coming in. Frequently divers wear undergarments under the scuba dry suit because they create layers of air inside the suit that improve thermal insulation. This means that a dry scuba suit can be used in a wide variety of water temperatures needing only to adjust the underwear type to go underneath. We must also consider when making the choice of underwear, the type and intensity of the activity we are planning to do and our body size.
Scuba dry suits are easier to put in and off than wet suits, but they also required specific and professional training (do not try to figure it out on your own!) and some practice to learn how to use them.
Scuba dry suits have a buoyancy control system incorporated to help you maintain neutral buoyancy. This is achieved through valves: an inflator valve (usually in the middle of your chest) and an exhaust valve (usually in the outside of your left bicep). On top of this, you must always wear a buoyancy compensator as a back up to guarantee you a surface flotation device (in the rare case that the one on the suit would not work). It is important to remember that it is very difficult to control both systems at the same time and to do so could distract you from the basic measures to have a safe dive, so do never use them together!

Types of Scuba dry Suits

There are basically two types of scuba dry suits:
  • Membrane suit: a material called trilaminate. This material is very thin (1mm) so it requires more protective thermal underwear than a neoprene one.
  • Neoprene. The material is very thick (7/8mm) which allows lighter on non underwear. In deep dives, neoprene can be compressed to 2mm, loosing part of its insulation properties. However, it is possible to buy pre-compressed neoprene to avoid this inconvenience.
A Couple of Tips about Scuba dry Suits

You may want to consider the following recommendations when planning to dive with a dry suit.
  • Check your suit a few days before the immersion: make sure waterproof zippers, seals and valves are in good condition and if not send them to repair.
  • When wearing the suit, your seals and neck seals must be correctly trimmed and adjusted. Latex seals are trimmed often till they are 15% smaller than your neck and wrist circumference. Neoprene seals need to be stretched over night: the neck on the widest part of the scuba tank and the wrist over a tin can.
  • Use the minimum amount of weight possible to help you achieve neutral buoyancy.
  • Make sure you choose a body that understands how your scuba dry suit works.
  • Practice, practice and practice till it becomes a second nature for you.
How to Maintain your Scuba Dry Suits

Rinse it well with clean fresh water after every dive. Check that seals, valves and zippers work correctly and have them fixed it not. You don´t need to rinse the inside unless is wet or damp (pay special attention to the bottom of the boots). Dry it out of the sun and without hangers. Do not storage it till it is fully dried to avoid mold and mildew.
The zippers should be lubricated wit bee´s or parafine wax.
For the seals you can use talcum powder or if you don´t have any, soapy water.
To storage it, roll it and put it in a sealed bag in a cool dry place, away from sources of ozone (like hot water heaters or electric motors).
In any case, consult your scuba dry suits manual for care instructions.