DIR-F swim requirement question

[Snowbear]

One thing I was recently taught about underwater swim tests (Our PSD team certifies with LGS - LifeGuard Systems - we have to go 25 meters... the length of the pool) ~ your body will tend to go in the direction the top of your head is aimed. In other words, if your face is forward, the top of your head will be towards the surface and you will have to work harder to stay underwater. If you face the bottom and just swim, it will be much easier to stay submerged once you're about 4' under.

Another thing this does is to help streamline you. Just like being horizontal instead of angled in the head up/feet down position so often assumed by divers. Being streamlined means you'll use up less O2 (and produce less CO2) to keep yourself moving forward.

It's also more efficient (uses less O's) to use a dolfin or frog kick rather than a flutter.

That said.... I suck at this test. It took supreme effort to pass the 60' test for GUE Tech1 and for me, the 25 meter LGS test is past the limit of what I can do without going beyond my physical limits. It hurt. I hated every second of it. And I was so dizzy when i finished that I almost passed out in 5' of water :11: Ugh! At least I don't have to do it again for 2 more years

 

[piikki]

nearly everybody should be buoyant with full lungs...

it helps if you get down 4' at least at the beginning!\0\05{\0\0\0\0\0\0\0\0compress and you'll be less buoyant and less likely to pop...

I am extremely buoyant, and never popped up even in shallow dive 'records' - just start letting air out if you get into danger zone towards the end, and use your arms to pull down. You'll go up if you are afraid of running out of air I think or like Snowbear said are diving in in wrong angle.

some things that i've found help are: fluid swimming, predominantly pulling with your arms, use your kicks to extend glides after you pull, but keep in mind that your leg muscles are big and use a lot of O2...

I always thought I was lame but I've found this to be true too. I hardly use my legs at all, and I can do two lengths in 40 f pool or 25 m pool once - with kick start from the end though. Kick from end should be allowed if you need to make a turn though because it takes such a nasty (puff) twist on your lungs if you are all panted out already I say.

 

[Xanthro]

How does this test relate to Scuba diving?

Just a confidence builder?

The key is to glide. Frog kick and bring your arms back at the same time. Glide as far as possible, then repeat. You want to save O2 and reduce Co2 buildup.

I've actually done 100 meters once, though that was off a starting block with a dive and a kick turn off the other end of the 50 meter pool. I've done 50 meters numerous times. BTW, when I did 100 meters, someone actually beat me, he simply kick turned again and got another 10 meters or so. I could have done that as well, but wasn't in shape to do another try. Also, I do NOT suggest swimming 100 meters underwater because it is very easy to pass out and is very dangerous.

 

[MonkSeal]

I am extremely buoyant, and never popped up even in shallow dive 'records' - just start letting air out if you get into danger zone towards the end, and use your arms to pull down.

Well, generally speaking letting air out in free-diving is not good practice:
a) when you descend your lungs have to be full to preclude lung colapse due to compression
b) when you ascend after some time letting air out in situation when ppo2 is already low (and getting lower due to air expansion) in not good decision

Of course, in particular case those two issues don't play big role.

 

[TSandM]

As I understand it, the big purpose of the breath-hold swim is that, in the event of a complete loss of air during a dive, you can swim to your buddy. Someone who is cave-trained told me that they will, when forced to move single file, allow some space to open up between divers, but not more than 50' . . . which is the length of the required breath-hold swim.

 

[MonkSeal]

How does this test relate to Scuba diving?.

Swim to buddy in OOG situation.

Just a confidence builder?

I believe that this is also a case and maybe a secondary goal.

 

[piikki]

Well, generally speaking letting air out in free-diving is not good practice:
a) when you descend your lungs have to be full to preclude lung colapse due to compression
b) when you ascend after some time letting air out in situation when ppo2 is already low (and getting lower due to air expansion) in not good decision

Of course, in particular case those two issues don't play big role.

I know absolutely nothing about free-diving (maybe I should). I always did my breathe-holds in the end of swimming sessions when training for other sports or just for fun in hotel pools. You get another nice boost when you slowly release the air that's burning in the lungs but yes - you do not want to be alone because it can get you light-headed. Generally it's always a challenge, so the other one is watching

 

[MonkSeal]

I know absolutely nothing about free-diving (maybe I should). I always did my breathe-holds in the end of swimming sessions when training for other sports or just for fun in hotel pools. You get another nice boost when you slowly release the air that's burning in the lungs but yes - you do not want to be alone because it can get you light-headed. Generally it's always a challenge, so the other one is watching

When diving in fresh water (like pool) you'll be negative bouyant with empty lungs (I'm negative with half empty lungs). Imagine yourself at the end of the dive tired, without enough strength to kick and letting air out and making you body negative bouyant. Not a pleasent experiance.

 

[Xanthro]

As I understand it, the big purpose of the breath-hold swim is that, in the event of a complete loss of air during a dive, you can swim to your buddy. Someone who is cave-trained told me that they will, when forced to move single file, allow some space to open up between divers, but not more than 50' . . . which is the length of the required breath-hold swim.

Then why not have the test done wearing the appropriate exposure gear and fins? That I could understand, but swimming in trunks without fins is nothing like swimming in gear.

 

[piikki]

Someone who is cave-trained told me that they will, when forced to move single file, allow some space to open up between divers, but not more than 50' . . . which is the length of the required breath-hold swim.

That's interesting. I had wondered if the fact that the breathe-hold happens without mask and fins (in addition to lost reg) is 'intentional' or just the regular testing dilemma. I would assume you very rarely lose both of your fins, and thus use more of your arms to move yourself and your kit to your buddy. (I am pretty useless without my fins in my exposure suit...)

I'd vote that it is not so profound 'exercise' but just there to scope out your general comfort - as swim test is to see that you can swim and are in some sort of a shape - more than eg check if your technique is perfect.