As a student or newbie, diving in a drysuit is challenging. It's tight, it's uncomfortable and it’s completely messed up what little buoyancy control they’ve learnt to date. And one related problem that never ceases to raise its ugly head is the issue of sinking.
As instructors we’ve all been there. A student or a NQ diver jumps in the water then after a few moments and much waving of the BC inflator later we hear that usual cry – “I can’t get under. I need more weight!”
Now it’s all too easy to throw a couple of extra kilos into a BC pocket and solve the immediate problem. But the issue then is your student may/probably will be over weighted which is going to lead to no end of buoyancy issues down the line that will provide even worse headaches.
So do yourself and your student a favour and resists the temptation to load up on the lead. Follow these simple tips and tricks below to make sure your student sinks like stone first time, every time.
Kit
Depending on what type of drysuit your student has will determine what undersuit is required. A trilam suit needs a thicker, more insulating undersuit than a neoprene suit that has some thermal protection built in; advise your students accordingly.
I’m personally not a fan of the “duvet” style undersuit. I have found that they hold a LOT of air and it’s not easily got rid off. More modern undersuits such as the Fourth Element Arctics, Otter Polar D and similar are made of a wicking fleece material that provides the same level of warmth, but in a much smaller thinner garment with better air migration. Pointing your students towards these thinner and less bulky undersuits from the start will make both your lives easier!
Should something more be needed to keep warm, these fleecy undersuits can be paired with a simple skiing type base layer which adds virtually nothing to the buoyancy characteristics of the undersuit but will boost the overall warmth considerably. My personal choice for winter diving is one I purchased from Decathlon worn under the Polar D system and it’s fab!
Pre-Dive
Many of the issues experienced by students can be alleviated by good dry side practice before jumping into the water.
The first tip is understanding the auto-dump on the drysuit.
I’m not sure where this comes from but I get this “3 clicks back from open” comment over and over from students. I even had one tell me once that “I prefer it 3 clicks back” which was interesting seems as he’d never been in the water with it at that point!
Shoulder dumps should be open or closed. There should be no in-between. If yours is leaking gas before it should then it needs a service, not partially closing!! When getting in the water and when diving it should be open. Fully open. It should only be closed when you’re out of the water to keep air in the suit to stay warm between dives.
So double check that shoulder dump on the student that just can’t get under, just in case!
The second is doing a good squeeze of the suit to get as much air out as possible before trying to get in.
Having a suit that hasn’t been pre-squeezed before you jump in isn’t just going to mean an age waiting for the air make its way through that (you’re sure it’s open?) shoulder dump, but it isn’t great for your drysuit either. The gas trapped in the suit will be instantly compressed into the shoulders and neck of the suit as you jump into the water and will put enormous pressure on the top seams and zip. Something akin to stomping on a packet of crisps.
I’ve only seen it once, but a chap popped his dry zip open due to the sudden pressure jumping into Capernwray. It wasn’t pretty.
And you’ll know the move and how to do it. If it was a yoga pose it would be called “Bear shitting in the woods” or “Traumatised child”. But basically, it involves crouching down, squeezing your arms around yourself whilst pulling the front of your neck seal open to allow the excess air to escape. Once done, replace the neck seal gently, stand up and you should look like a piece of vac-packed meat – Sexy!!
In Water
Weight Check
Sounds simple enough, but when I ask people who are finding it difficult to get under or are struggling with their buoyancy when they last did a weight check, too often I get a blank look in return!
Skipping a decent weight check at the start really isn’t doing you or the student any favours. A weight check will give you a solid base from which to start and once you have this, you can move onto some of the other tips and tricks below safe in the knowledge that they really aren’t underweighted.
I normally do a weight check with the students not wearing fins and although it does mean you have to drag them around a bit, it does solve the problem from the tip below whilst you’re doing the check!
Finning
When a human throws itself into water, it instinctively knows that sinking isn’t a great idea and will start doing whatever it can to prevent that. This normally involves swimming or treading water. Stick that human in a pair of fins and they become much better at preventing themselves from sinking. Sometimes, so much so that they can’t sink, even when they want to, as they simply won’t stop finning!
Now most students don’t even realise they’re doing it or that it’s a problem and most will be able to stop when told to do so and the problem will be solved.
I have come across a few though that despite being told to stop finning, they simply can’t seem to. The survival instinct must be especially strong in these!! I must admit, they tend to be the nervous ones as a rule.
So if you’ve got a student or NQ that can’t sink, stick your head underwater and see what their feet are doing, chances are they’ll be finning upwards constantly.
The simplest way I’ve found to deal with these “constant finners” is, when it comes time to head down, tell them to cross their legs until they’re a couple meters down and ready to get into trim. Problem solved!
If you doubt me, you try finning with your legs crossed and let me know how you get on!
Breathe Out
Have you ever paid any attention to what you do with your breath just before you jump into the water? I’m willing to bet it’s take a big breath in, then jump off. Most people do this. I know I certainly do, even to this day. Again, it’s preparing yourself for jumping into the water and it’s perfectly natural.
The difference here between an experienced diver and a novice, is that your experienced diver will quickly settle once in the water and will breathe out fully when descending but, chances are, your newbie will keep their lungs as full as possible and “breathe from the top” – And by this I mean they let a little bit of breath out, but not much before they’re breathing in again.
Now if we think back to our first scuba theory lessons, we we’re taught about lungs (if you’re BSAC anyway). You’ve got your Tidal Volume, Vital Capacity, Residual Volume and all that jazz. But the upshot of it is, you’ve got about 4kg of lift you can play with just by breathing.
So does that student need 2kg of extra lead or do they just need to breath out a bit more and lose 2kg of buoyancy?
If your student is still bobbing around on the surface like some kind of flaccid teabag despite doing all we’ve talked about above, I’m willing to bet that they are not breathing out properly.
One exercise you can do with your students, and get them to practice this even before getting kitted up, is what I call the “Super Exhale” – It’s a technique I’ve recently been shown and is something that’s used by free divers so I’m told. It works anyway wherever its origins.
Here’s how you do it…
From a normal or full breath, breathe out. One you’re at the bottom of the breath, take a short sharp breath in, then breathe out again. You’ll find that after that short, sharp breath in, you can breathe out further than last time. You can do this a number of times until you’ve got right down to your residual volume. Once there, you should be getting on to being 3-4kg less buoyant than before and sinking like a stone!
And that’s all folks!! If you’ve followed all these hints and tips, you should never again hear that desperate yell for more lead!!
You’re welcome.
Do you have any other hints or tips you can give the UKDiver community? If so share them down below in the comments section. We’re all learning every day and I’m never one to look a good tip in the mouth for sure!
Comments