How much weight do put in my bc???

[August470]

Hi im new to diving, and i am trying to figure out how the hell do i figure out how much weight to put in my bc. i bought my own and i need to buy weights. i'm still a student and will be certified by next month. the amount of weight that i had in the pool class want enough. any amount of air made me feel unstable at the bottom. help. thank you in advance.

 

[buddhasummer]

As you are still doing your course I think speaking with your instructor about this would be the best way to go. You need to do a proper weight check as per your OW manual and your instructor can walk you through this.

Often when someone begins diving they have a tendency to use too much weight but as they gain experience (more relaxed, breathing etc) will often drop a few lbs.

I'm assuming you have a weight integrated BC this being the case you might want to consider how you will distribute your weight e.g some in weight pockets some on weight belt. Ideally you want to achieve good horizontal trim in the water. Also worth considering in weighting is possible equipment failure (losing weight belt, BC failure). For example I carry some weight on my BC and some on a weight belt, if I lose my weight belt I will not rocket to the surface as I have not lost all my weight, if my BC fails I can ditch the weight belt if necessary and will not be completely positively buoyant as I have some weight on my BC. How much weight you need varies from person to person, thickness of wetsuit (thicker=more buoyancy), type of tank used (steel- or aluminium+), slat or fresh for example.

"...you should be neutrally buoyant during your 15-foot / 5-meter safety stop at the end of your dive with between 300-500 psi / 20-34 bar in your tank and no air in your buoyancy control device (BCD). If you remain motionless and you sink, you’re overweighted. If you start floating to the surface, you’re underweighted. Adjust your weight on the next dive accordingly..." (DAN).

Doing a weight check at the end of a dive is ideal. If at the end of a dive with 500psi in your tank, no air in your BC and holding a normal breath you float around eye level then your weighting is pretty good, sink like a rock then too much, cannot sink too little, as you exhale you should begin to SLOWLY descend. Use some of the time you have left in your OW course to get your weighting dialed in. Being properly weighted makes diving both more enjoyable and safer. I'm sure some more experienced members will chime in. Good luck and welcome to Scubaboard.

PS this is a good article:

Scuba Buoyancy Masterclass 4of9 - Assessing Your Weight RequirementsScuba Tech Philippines

 

[USCScubaboy]

I would hold off on buying weights until after your OW class. Perhaps even until a while after the class.

I did my OW class in a jacket style BC and the dive shop I took the class which supplied all of the weights I used during the class. After the class, I went and bought a bp/w and 20 lbs of weights. After 70 or so dives, I now only use 8 lbs of lead (in addition to my backplate) when I dive a 7 mm wetsuit and a steel tank. Luckily, I recently switched to diving a drysuit so I can still use the weight that I originally bought.

 

[Bubbletrubble]

buddasummer wrote up an excellent response. I second his advice.

I realize that some instructors/shops require their students to purchase lead weight for basic OW class, but they are definitely in the minority. Most shops here in SoCal include weights with all of the rental gear (reg, tank, BCD, wetsuit) and ask the students to purchase "personal gear" (gloves, hood, mask, snorkel, booties). Purchasing weights at the beginning of OW class makes little sense because beginner divers do a variety of things (funky breathing, surreptitious kicking, tensing up, being anxious, etc.) that make their weighting requirements wander all over the map.

One of the many important skills I learned in basic OW class was how to do a proper weight check.
We did weight checks before and after every in-water session.
Ask your instructor to teach you the elements of a proper weight check. As a novice diver, it probably wouldn't be a horrible idea to do a weight check on every dive. You might be renting new-to-you gear, wearing a new wetsuit, using a different tank, breathing more "normally," or simply becoming more comfortable in the water and all of these changes justify doing a weight check. Even as you become more experienced, a weight check is warranted whenever you add/subtract/replace gear.

Don't forget to record the results/details of your weight check in your dive log. Among other things, the log serves as a reference for how much weight you need to wear with various gear configurations (tank, exposure protection, fins, BCD, etc.) and in salt vs. fresh water.

Enjoy the rest of your class!

 

[DevonDiver]

One of the many important skills I learned in basic OW class was how to do a proper weight check.
We did weight checks before and after every in-water session.
Ask your instructor to teach you the elements of a proper weight check.

If your scuba course is with PADI, then it is a training standard (obligatory for the instructor) that he teaches you to perform a basic weight check on module 2 of the confined water training. As with all skills, that weight check needs to be performed "with mastery" before you progress on the course.

Confined Water Dive 2 Performance RequirementsAt the surface:
1. Perform the buddy predive safety check.
2. Demonstrate appropriate deep-water entry.
3. Clear a snorkel using the blast method, then resume breathing through it without lifting the face from the water.
4. Exchange snorkel for regulator and regulator for snorkel repeatedly without lifting the face from the water.
5. Swim at least 50 metres/yards while wearing scuba and breathing through a snorkel.
6. Adjust for proper weighting — float at eye level at the surface with no or minimal air in the BCD and while holding a normal breath.
7. Orally infl ate a BCD to at least half full in water too deep in which to stand, then fully deflate it.
8. Remove weights using the quick release mechanism with minimal assistance
9. Remove weights, scuba unit and fins (if necessary) in water too deep in which to stand and exit using the most appropriate technique. (Buddy assistance allowed.)

Most other agencies will have similar standards - as it's critical that divers understand proper weighting before they progress into the open water environment.

If you didn't do this by the end of your second pool session, then your instructor might not be adhering to training standards. That should be investigated and resolved asap.

 

[Bubbletrubble]

@DevonDiver: Thanks for sharing the quote from the PADI instructor manual. It sort of sounds like the OP has had only one pool session so far, so the instructor still has some time to teach the weight check.

I do find it peculiar that the OP was asked to purchase lead weight...when he/she hasn't even been taught how to do a weight check yet and, therefore, has no idea how much weight is needed.

@August470: I forgot to mention that beginner divers almost always feel "unstable" in the water, regardless of whether they are properly weighted or not. In my class, I recall kneeling down in the shallow end of the pool and falling over to the left...and the right. I couldn't hold still. The entire class was like that. We looked like a bunch of drunks. Fortunately, better balance comes with experience. FYI, with a full tank, if you are properly weighted, you should have to add a little air to your BCD.