ADVERTISEMENT

Author Topic: Under what circumstances that a diver needs to dump weight?  (Read 5123 times)

poh6702

  • Member
  • ***
  • Posts: 585
  • Liked: 74
  • Karma: +40/-9
  • Singapore Scuba Diving Forum
can share the link?

Found this form Youtube:
http://www.youtube.com/watch?v=ANivWvpmkhM

The one about diver lost weight belt is at about 5 minutes.
« Last Edit: 07 Jul 14, 16:52 by poh6702 »

epwing

  • Jr. Member
  • **
  • Posts: 27
  • Liked: 2
  • Karma: +0/-0
  • Singapore Scuba Diving Forum
This topic seems to comes up every so often, perhaps we can make it a sticky... ;D

You'll need to dump weights if you're:
1. Wearing a 5mm or 7mm wetsuit and your BC fails to inflate at the start of the dive. Your tanks are full of gas and your suit is fully compressed.

2. Carrying multiple gas tanks, stage bottles, deco bottles in a wetsuit and your BC fails to inflate at the start of the dive. You will be very negative at this stage and will not be able to swim up.

3. Your rig is severely overweighted and your BC fails to inflate at the start of the dive.

For point 1, 5mm and 7mm should make you more buoyant than a 3mm and not the other way round. Wet or dry.

And for all points here that you have listed, are simply one point that BCD fails to inflate. Which shouldn't have happen if a thorough equipment check is done properly.

Beside it is a safety procedure to inflate BCD a little prior to any dives. Even if you have forgotten, the reaction is to fin your way up and reach for inflator and not release your weight belt.
« Last Edit: 07 Jul 14, 21:12 by epwing »

epwing

  • Jr. Member
  • **
  • Posts: 27
  • Liked: 2
  • Karma: +0/-0
  • Singapore Scuba Diving Forum
The key is practice your dive and carry as less weight as possible. Myself carry 2 pound weight due to natural buoyant, wet suit and SMB. I have seen new divers carrying 18-20 pound due to their size and probably their inexperience to overcome the first 5meters to sink initially. This may be a dangerous start even before they dive. If he loses the belt underwater, the result is unthinkable. If he really needs to carry that much weights, a split of weights into two belts will be a safer bet.

I will hold-on to my dear belt anytime than to let it hung and run loose.

epwing

  • Jr. Member
  • **
  • Posts: 27
  • Liked: 2
  • Karma: +0/-0
  • Singapore Scuba Diving Forum
I have read somewhere about buoyant emergency ascent. Situation when one run out of gas underwater alone or without a buddy beside for an alternate air source. This is where you will ditch all your weight belts and reach for the surface. Flaring your arms and legs to create drags and exhale air all the way. And hopefully to live to fight the current another day.

Crash

  • Member
  • ***
  • Posts: 56
  • Liked: 17
  • Karma: +2/-0
  • Gotta Live Before You Die
    • Google
For point 1, 5mm and 7mm should make you more buoyant than a 3mm and not the other way round. Wet or dry.

And for all points here that you have listed, are simply one point that BCD fails to inflate. Which shouldn't have happen if a thorough equipment check is done properly.

Beside it is a safety procedure to inflate BCD a little prior to any dives. Even if you have forgotten, the reaction is to fin your way up and reach for inflator and not release your weight belt.

Not true, 5mm and 7mm wetsuits have different buoyancy characteristics on surface and at depth. On surface its is very buoyant, but at depth the air in the wetsuit is squeezed and thus provides little buoyancy. At this point at you will be negative and gotta compensate with your bcd accordingly. Which is why it is advisable to use aluminum tanks and not steel tanks with thick wetsuits. Steel tanks are reserved for drysuit diving where the drysuit's buoyancy can be manually adjusted at depth. Those that have dived in cold waters would know this.

And BCD can still fail despite proper equipment checks. I know this because a good friend of mine who was using a brand new bcd a few months back had a catastrophic bcd failure in the water. The area where the elbow of the corrugated hose joints the bladder completely gave way. No one would have expect that a brand new BCD which was checked prior before the dive would failed. I've also seen a few rental bcd fail during the dive as well. I think one of the guy who had experienced it is here on scubasg.

Best advice imho is to be properly weighted by diving a balanced rig. even if the bcd fails, you will still be able to stay ascend by dropping your ballast (weight belt) and fin. DIR practitioners would be familiar with this.

« Last Edit: 07 Jul 14, 23:35 by Crash »

antacid

  • Sr. Member
  • ****
  • Posts: 1262
  • Liked: 33
  • Karma: +14/-12
    • Colouredshots
ditching your weights is more applicable if you dive in colder waters and wear thicker wetsuits or drysuits and need a lot more weights.

yes, 1 or 2 weights doesn't sound like much now. But it would feel like 2 tons to you if you suffered a catastrophic failure and needed to do a CESA from 20m and your tank is dry.

yes by right you should have checked your equipment, by right you should be properly weighted, by right you should have more than enough air.

you did all of these, that's why you're able to do a second dive. but crap happens, that's why we have diving incidents.

epwing

  • Jr. Member
  • **
  • Posts: 27
  • Liked: 2
  • Karma: +0/-0
  • Singapore Scuba Diving Forum
Not true, 5mm and 7mm wetsuits have different buoyancy characteristics on surface and at depth. On surface its is very buoyant, but at depth the air in the wetsuit is squeezed and thus provides little buoyancy. At this point at you will be negative and gotta compensate with your bcd accordingly. Which is why it is advisable to use aluminum tanks and not steel tanks with thick wetsuits. Steel tanks are reserved for drysuit diving where the drysuit's buoyancy can be manually adjusted at depth. Those that have dived in cold waters would know this.

And BCD can still fail despite proper equipment checks. I know this because a good friend of mine who was using a brand new bcd a few months back had a catastrophic bcd failure in the water. The area where the elbow of the corrugated hose joints the bladder completely gave way. No one would have expect that a brand new BCD which was checked prior before the dive would failed. I've also seen a few rental bcd fail during the dive as well. I think one of the guy who had experienced it is here on scubasg.

Best advice imho is to be properly weighted by diving a balanced rig. even if the bcd fails, you will still be able to stay ascend by dropping your ballast (weight belt) and fin. DIR practitioners would be familiar with this.


I understand that air get compressed and bubbles in wetsuit break down in depth. The point bare bear discuss is on the surface, hence it shouldn't be compressed, should be buoyant. Try it wet or dry on the surface, you never get negative.

And you are probably missing the point here, BCD failure on the start of dive doesn't warrant an immediate ditching of weights. You can fin to the boat for safety, beside, you still have the regulator in your mouth.
« Last Edit: 08 Jul 14, 00:21 by epwing »

Crash

  • Member
  • ***
  • Posts: 56
  • Liked: 17
  • Karma: +2/-0
  • Gotta Live Before You Die
    • Google
I understand that air get compressed and bubbles in wetsuit break down in depth. The point bare bear discuss is on the surface, hence it shouldn't be compressed, should be buoyant. Try it wet or dry on the surface, you never get negative.

I think what he meant by 'start of the dive' is when one has already descend to depth with a full tank at the point the 'suit is fully compressed'. Please correct me if i am wrong barebear.

epwing

  • Jr. Member
  • **
  • Posts: 27
  • Liked: 2
  • Karma: +0/-0
  • Singapore Scuba Diving Forum
I think what he meant by 'start of the dive' is when one has already descend to depth with a full tank at the point the 'suit is fully compressed'. Please correct me if i am wrong barebear.

Then it will get more puzzled on why he will need to inflate BCD when diving down, only to know that BCD is faulty and he ditch the weight to go up again uncontrollably. This is dangerous boy. Keep your weight, trust me.

epwing

  • Jr. Member
  • **
  • Posts: 27
  • Liked: 2
  • Karma: +0/-0
  • Singapore Scuba Diving Forum
The point here is simple. You ditch your weight during emergency. What emergency that you will give it all to save youself; You run out of gas (tank or reg equipments failure and your buddy is not around you). And not any other equipments failure. I hope it makes sense.