How much harder is it to freedive in cold water?

[Stavros]

Since I've never taken a freediving course I can't speak from experience but I can ask this question:

Who says the instructor has to be the safety diver as well? Quite frankly a setup like that should not be allowed. The instructor is there to teach not to act as a safety diver. The "job" titles should be completely separated with no carry over permitted.

The instructor should ALWAYS be on the surface/out of the water.

Just my opinion,
Ryan

1. The instructor is the organiser and person responsible for any course and he must be able to ensure the safety of the students if something goes wrong. The instructor can choose to have extra safety divers but I 've rarely or never heard of that happening (maybe more than one instructor in a class but never specifically designated safety divers)

2. How is the instructor supposed to observe the technic of the student if they stay on the surface?
(Think of a 25m dive with 5m visibility in the UK)

3. Who demonstrates during the course if the instructor stays on the surface / cannot dive.

You would be happy with a course were your instructor stayed at the surface?
My students would definately not be - one of the things that students really benefit from is seeing an experienced freediver move in the water...

Cheers Stavros

 

[samdive]

Ryan - it's not about whether he is allowed to join us, if you read the post you'll see it's about how much less depth he/she can expect to achieve in colder water, thicker suit.

Research on learning - done a fair bit of that as a scuba and freedive instructor trainer and having worked for several years as a Training Consultant for PADI but thanks for the advice anyway....

We have a saying in PADI - RTFQ!

It stands for READ THE F*** QUESTION!

 

[samdive]

Good points Stavros - of course the instructor should be in the water - how else can you teach? We usually have two instructors in the water and dive with every student - or at least whenever they go out of sight (in 5m vis).

Sounds like about a 5-10m drop might be normal - which is what I thought so I'll stick with that advice in future. I'd never put the plate at someone's Dahab PB the first time they came to the lake, just not safe- but I'd consider 5m less as a start point.

Thanks for the constructive info

S

 

[apneaboy]

If we are taking the scenario of a diver coming from Dahab for their first UK dive and taking off 5-10 metres off their pb are we then recommending a diver who dives in colder fresh water go to Dahab for their first sea dive, with a bit of chop, different density water so having weighting issues and put on 5-10 metres on their pb then??

That wouldn't be prudent either.

I think an instructor going for the performance requirements to get their instructor ticket can wear a thinner suit for a single dive and then train students in a thicker one if they are going to be in the water for a couple/few hours if they thought they would have a problem.

 

[Stavros]

Good points Stavros - of course the instructor should be in the water - how else can you teach? We usually have two instructors in the water and dive with every student - or at least whenever they go out of sight (in 5m vis).

Sounds like about a 5-10m drop might be normal - which is what I thought so I'll stick with that advice in future. I'd never put the plate at someone's Dahab PB the first time they came to the lake, just not safe- but I'd consider 5m less as a start point.

Thanks for the constructive info

S

All this talk about diving in the UK is making me sooo curious...its a shame I have no trips planned to the UK in the foreseeable future...

Maybe next year.

Cheers Stavros

PS. I would have to say that if I went for a max dive (my current pb is in the high 70s in warm water) in a cold dark lake I would reduce my max depth (I'd probably do a first dive to 60 and then the next session I 'd try 70 depending on the feeling) but I think that’s because I know that the high 70s in good conditions with divetimes of 2:20-2:40 is getting me quite close to my apnea limits. For a person with limited experience who is mainly being stopped by equalisation or fear of depth etc I would not say that the reduction would have to be so big. (on the other hand if I just wanted to have fun I would say to set the line at 80 and go by the feeling roflwhich is why I suggested the 0 reduction in depth :t)

 

[harbour seal]

interesting dicussion everyone.

Also note that the penalties for various wetsuits differ, based on if the diver is packing, or not packing, or FRC diving. An FRC diver generally suffers less of a penalty for a thick wetsuit, especially for middle depth dives.

eric,

could you explain the bit about frc divers having less of a penalty? is this due to less overall lung compression and thus less buoyancy change?

in general, i am still a little confused about buoyancy change and its effect on a dive. does less buoyancy change means less effort overall? but doesn't buoyancy change essentially cancel itself out in that you sink easier as lungs/suit compress (descent) and ascend easier/faster as they re-expands.

cheers,
sean
vancouver, canada

 

[BennyB]

Come on Stavros, get your finger out and come on over! I'll buy the first pint

 

[samdive]

Yup Stavros - and you can tell me your PB before you come out and see what you can do in the lake

come to think of it - any more warm water divers out there want to make this into a real experiment rather than a web discussion???

saltfree meet tomorrow - and again 27/28 October...

S

 

[m2b]

A little off topic but still on topic at the same time.

In the beginning of the thread some of the possible things mentioned as causing problems/needing to be "weighed" was water temp, bad vis, and current. When you guys speak of current causing trouble what are you referring to? What is the source/s of the current and how does it effect you, including at what kind of depth? I had a rather unique experience today that I'm questioning if it was current problem or what the heck was going on. It really caught me off guard, on two completely separate bodies of water.

Ryan

 

[Fondueset]

Harbour Seal,

I think you're basically right about what Eric said. For example - with a 3 mil suit vs 5 mil there is dramatically less change due to suit compression - because the suit has less air volume. Same with lungs. consequently less effort going down and coming up - also less effort swimming along the bottom. FRC divers can also dive with less weight.

 

[amihov]

I want to add something about cold and warm water. I know i am not a big expert but i have been diving for about 2 years now. In Vancouver i am diving whit a 7 mm suite and i have about 10 kg lead on my belt. Going down is hard and going up is worse i live the sea live in Canada it is one of the best places but i have to say it is so much easier if the water is warm. This summer i was diving back in Bulgaria water temperature was around 26 c all the time. I was spending more then 1 hour in the water on wet suite no weight belt. Going down to 15 meters for me was just like a child play . Swimming up the surface only took about 2 kicks it was soooo much easier . I was doing thining that i have never done before in vancouver i was going down 15 meters and spending time taking pictures swimming around for atleast 25- 30 m on a 15 meters dept searching for fish. And when the time to breath comes up all i did is just kick 2 times and i was on the surface . Warm water no suite is the best diving and the difference is huge comparing whit a cold water diving. Again cold water is fun to but the it is much harder because of the suite and the weights.

 

[harbour seal]

fondueset,

of course, less air volume in the suit, thanks for the reply. for some reason buoyancy change is hard for me to wrap my noodle around. using my 6mm/5mm elios wetsuit, i dive frc with more weight than inhale; it is the only way to be able to sink from the surface after one or two kicks. it would be great to dive frc in warmer waters using less weight.



amihov,

thanks for the excellent trip report comparing vangroover and those sweet sounding tropical waters of bulgaria. i would love to dive in 26 degree water. no wetsuit and no weights sounds like heaven. i still love our emerald green waters, even as frigid as they may be.

cheers,
sean
vancouver, canada

 

[amihov]

I really like diving in Vancouver . I have seen many interesting things in our local waters. One thing i need to say is i have the feeling that you are using to much weight. Be careful you should be able to start sinking around 7 to 8 meters when you have a wetsuite. If you are sinking from the first 3 meters you may have some problems if you go under 12 meters. Check the weight . I had some bad experience in Vancouver where i was using way to much weight . You may have some hard time getting back to the surface .

 

[harbour seal]

I really like diving in Vancouver . I have seen many interesting things in our local waters. One thing i need to say is i have the feeling that you are using to much weight. Be careful you should be able to start sinking around 7 to 8 meters when you have a wetsuite. If you are sinking from the first 3 meters you may have some problems if you go under 12 meters. Check the weight . I had some bad experience in Vancouver where i was using way to much weight . You may have some hard time getting back to the surface .

amihov,

i appreciate your consideration regarding the weight and potential problems.

regarding my extra weight, i am diving the frc (functional reserve capacity) style where you passively exhale before descending (also known as exhale diving). to use this technique effectively you need to sink from the surface (or thereabouts) and passively descend; the entire descent should essentially be a static. in order to be able to sink like this, while wearing a wetsuit, you thus need to be weighted heavier than when diving on full inhale.

i am far from being an expert, as i only switched over completely to exale at the outset of the summer. i am diving frc in the 10-20m range, which is as deep as i have been on inhale as well. as far as the amount of weight, this required a little trial and error with different amounts before i found what felt right. as of yet, i haven't experienced any problems with the added amount of weight. others feel free to chime in here if i am off base.

sorry to sidetrack this thread from the cold water discussions. if anyone is interested, there are a bunch of excellent threads here on db detailing this style of diving. search for "exhale" or "frc" and especially look for posts by sebastian murat and (of course) eric fattah.

cheers,
sean

 

[Fondueset]

That's interesting Harbour Seal. I know about the weighting in FRC But since I dive alone alot I like to be positive at the surface. Makes for easy breath-ups and easy ascents. Now that I'm back in my 5 mil the compression diff is really noticeable. When I'm swimming with my monofin I have to swim much faster to stay off the bottom at 10-15 meters. I'm thinking about going with even less weight! I'm not doing FRC except in 3-5 meter depths as a way of adjusting buoyancy but I wonder about the energy trade off - easy descent vs easy ascent and easier bottom swimming.

 

[laminar]

Sean,

It doesn't make sense to be that you would need more weight for FRC than you would for inhale diving because of the great amount of buoyancy that a few extra litres of air represents. But I trust that you've tried everything out. One question, are you neutral, negative or slightly buoyant at the surface? While it is wonderful to sink from the surface, you also need to factor in the energy cost of staying off the bottom once you get down there and the cost of staying on the surface if you sink beneath it during a breathe up.

I find that when I wear a 6.5/5mm combo it's a little more tricky to get the right weighting for dives of variable depth. These days I spend most of my time in the 10-20m range for video and photography) with the occasional fun dive to 30m+. So I try to find a weighting that allows for the odd deeper dive. I really hate to be negative on the surface because it's hard to relax. The compromise I usually make with my weight belt is to need to breathe higher than FRC during my breathe up, so that means never exhaling fully, or if I do, it needs to be done quickly, because I'll start to sink slightly, enough to make an inhalation somewhat more difficult. This isn't perfect, but it seems to be the best weighting for when I'm starting the dive and when I'm down underwater. It all depends on the underwater topology as well. If you are slightly more weighted and you are crawling down a steep wall, keeping yourself away from it with a finger on a rock now and then, it's going to be fine. However, if you're trying to stay off a flat bottom, it's going to be a pain and you'd want to dive with a little less weight.

This weighting also means that when you reach the surface at the end of a dive and take a deep breath, I'll be buoyant. If you want a higher margin of safety, then it would be best to be slightly buoyant on the surface, even with no air in your lungs. Lots of tradeoffs. Waste energy during the dive and have a problem at the surface or conserve energy during the dive and dive more conservatively so that you can manage yourself on the surface.

Diving with no suit is a dream with FRC. A 3mm is no bad, but I find myself buoyant in weird places (like the head), which makes things a little awkward.

Amihov,

7 mm seems like too much for Vancouver and 10 kg is a lot of weight. You may need to learn to embrace the cold a little more and enjoy being able to swim more easily. But everyone has their own preferences, of course.

I'm diving without fins these days. The weight of a monofin does make a difference and of course gives you more range given a certain weighting. I'd say the range is much less with bi fins.

Pete

 

[Fondueset]

I use a 6 mil smoothskin out for winters around here - thats with 3c water. Though I've done a winter in a 5 mil with no problem - just somewhat shorter dives. I have to say the smoothskin makes a HUGE difference in warmth. Heat loss during breathups in cold weather is a major factor and the smoothskin suits wick much less heat away.
30meters with no fins!
What about fish stalking? With some species here I have to minimize movement in order to get close that includes the trip down.

With the 6 mil compressibility is such a factor that I can be neutral at 7 or 8 meters, float like a cork at the surface and still be sluggin along at 20 meters. 3 mil seems like about the nicest suit thickness.

 

[harbour seal]

pete,

it is great to hear from someone with so much diving experience, particularly with the frc style in cold waters using a wetsuit. i very much appreciate your input.

buoyancy issues have been bit a bit confusing to wrap my head around, thus i really don't know whether the weight i am using for frc makes sense or not. let me explain the process i went through and perhaps it will help clear the waters, so to speak.

most of the summer i dove with only a 2mm vest/hood/2mm shorts using 4lbs on my waist and 2lbs on my neck. using this amount, i was positive on the surface during breathup (more weight made me negative), although higher waves were somewhat problematic. after exhaling, i would do 3-4 kicks and then sink. i spent most of the summer diving in this fashion for 90 min sessions in the 8-15m range; however, i would be fairly hypothermic by the end of a session, requiring 3-4 hours to warm up.

at the end of august, i started using my 6mm/5mm nylon-out, new black coating in, elios suit. initially, i found i was way too hot and had to cool off by frequently flushing or diving with the hood down. it seemed to help markedly if i swam for awhile to cool down before suiting up. using the suit allowed me to stay in the water for much longer (approx 3 hours) and not be cold when i came out, which can be laborious after awhile.

regarding the weight, i built a 16lb custom weight harness (see http://forums.deeperblue.net/freediving-equipment/50512-diy-soft-weight-harness.html#post664882), which is equivalent to the weight i previously used on my belt for inhale. using 16lbs on inhale i am neutral at approx 8-12m, an estimate made during my first few freediving sessions the previous winter.

wearing the harness for frc (with my wetsuit), i found i was too buoyant (after passive exhale) and didn't really start sinking until approx 5m. i tried experimenting with different amounts of weight and eventually found that adding 4lbs on a waist belt and 2lbs of ankle weights seemed about right (total 22lb). using this amount, i am positive on the surface during breathup and after exhaling i do two or three kicks and start sinking. using more weight i found i was negative after exhaling during breathup, which is a pain in the butt and led to many flooded snorkels, not to mention it was nearly impossible to relax face-down in waves.

another benefit of this setup is the weight harness (the majority of my ballast) shifts my centre of gravity farther down towards my head, thus making head-down sinking easier. additionally, the ankle weights have the added benefit of helping to keep my legs down when i lay on the bottom.

regarding the added energy required to stay off the bottom you mentioned, i hadn't yet considered this as an issue. i expect it is because my dive times are quite short thus i don't have too much time for exploration along the bottom (usually in the 40-60 sec range using frc---more on inhale). i generally use an aspetto approach even though most of my sessions have been strictly freediving (not hunting). lying motionless on the bottom (or holding onto a wall), i can watch the shrimp dance in the sand and the resident fish will come over and check me out. also i often enjoy slowly crawling along the bottom pushing myself along using my hands. using a smooth skin open-cell wetsuit i would expect you need be careful to stay off the bottom, especially compared to my approach using a nylon covered suit.

the only other factor i can think of regarding my buoyancy and associated weighting between exhale and inhale is the size of my lungs. i think i may have smaller lungs than most, thus the difference between a full inhalation and a passive exhale might not be as much for me as with others.??? although this ratio may be constant regardless of lung size???

over the winter i am planning to order a 3mm elios suit for use during the summers, as my current wetsuit was too hot. from all reports this should be much nicer for diving than my current suit, which i already find pretty darned sweet (if i don't get too hot). i can't wait!

finally, you are diving without fins? how do you find swimming with neoprene socks? a while back, i read that tyler z was doing this after his fins were stolen. perhaps you guys are starting the next trend to sweep through colder water diving (frc being the last).

cheers,
sean
vancouver, canada

ps. i welcome insight/comments/opinions from everyone

 

[Fondueset]

I was just out in my 5 mil. I have 10lbs on my belt at 2 in my vest (just enough to help keep the upper body down. Its shallow quite far out in my fav spot right now so I am mostly swimming along the bottom out along some old pipes - I'll swim out about 500 meters or so, then over to the breakwall to visit with the fish. Max depth is only about 10 -12 meters and I'm allready too negative starting at about 9 (neutral at 5 or 6)- I am not diving frc! Now, I may have less body fat, or smaller lungs or whatever, but it seems to me you might be a bit overweighted for frc. For my 6 mil I might add 2 - 4 lbs - for a max of 16lbs - but probably only 2 as I tend to dive in a deeper area - still only 15-20 meters - when the water gets really cold and clears up.

How is your entry? It may be you don't even need those first few kicks!

Everybody's different - but I like to be able to glide along the bottom and enjoy the ride up

 

[harbour seal]

...Now, I may have less body fat, or smaller lungs or whatever, but it seems to me you might be a bit overweighted for frc. For my 6 mil I might add 2 - 4 lbs - for a max of 16lbs - but probably only 2 as I tend to dive in a deeper area - still only 15-20 meters - when the water gets really cold and clears up.

How is your entry? It may be you don't even need those first few kicks!

Everybody's different - but I like to be able to glide along the bottom and enjoy the ride up

fondueset,

i always pay close attention to advice from wise forum members such as you and peter. i am but a mere novice diver out exploring my love affair with the water, and open to any means of deepening my immersion.

i have only been freediving for less than a year thus i know i have much to learn. things like my entry and bottom time need improvement, although i do conciously try to minimize any unecessary thrashing. unless i were to do something as silly as losing my mask, then i thrash profusely . from what i read here, it is more than likely i will need to lighten my set-up as i improve, especially if diving deeper than my present range of 8-20m. my current weight configruation does afford me the ability to sink without much effort, which is a most sublime feeling.

in the near future, i hope my frc bottom time improves so i can spend more time gliding along the bottom as you describe.

cheers and thanks,
sean