First boat dive - how much weight?

[adjuster-jd]

I will be taking my first boat dive in Hawaii in June after completing my OW cert at a local quarry at the end of May.
Since the boat dive will be my first dive (after cert) in salt water, how do I know how much weight I will need in salt water? How do I make sure I have the proper amount of weight before entering the water?

Thanks in advance for your help.

 

[MechDiver]

adjuster-jd once bubbled...
I will be taking my first boat dive in Hawaii in June after completing my OW cert at a local quarry at the end of May.
Since the boat dive will be my first dive (after cert) in salt water, how do I know how much weight I will need in salt water? How do I make sure I have the proper amount of weight before entering the water?

Thanks in advance for your help.

The resort/dive op you are going to will be able to help you, as that is one of their duties. They may require you do a checkout dive anyway before they will let you dive on the boat.

MD

 

[WreckWriter]

We'd need a lot more info to even hazard a guess. Your physical size and body type, exposure suit type, tank type, amount of weight you used in fresh water (and exposure suit and tank worn there) at least.

Mech's recomendation is best, talk to the crew, they'll help you out.

WW

 

[Charlie99]

_IF_ you are using the same amount of wetsuit, then the adjustment for going from freshwater to saltwater is to remove about 2-1/2 pounds of lead for every 100 pounds of total dive weight. Total dive weight is you, plus your gear including tank and weights.

For most people, this means you add 6 to 8 pounds.

It is better to start a few pounds heavy, then remove a pound or two with each dive until you get it right. If you have 500psi in your tank, and there is any air in your BC at the end of your dive, then you can remove another pound or two.
------------

Remember to empty your lungs by exhaling strongly, and keep your feet still to make your initial descent. I've seen a lot of new divers suck in a huge breath of air just before they try to descend --- this is scuba, not snorkeling; your air comes with you <g>.

Have fun in Hawaii!

Charlie

 

[jbd]

meant to say you add not remove when going from fresh to salt water.

 

[annie]

Tip: I always record all the 'weight factors' in my logbook. I note down lead weight, suit, type/size of tank, fresh/salt and whether I was too heavy, whether I experimented, did buoyancy test etc.

If I change any of those things i.e. go to a different location, or haven't dived in a while etc - I can look back in my logbook and estimate what changes I should make to my weigt belt. It will also help anyone you ask for advice! I think this has saved me a lot of time trying to work it out.

 

[adjuster-jd]

Ok, maybe I should clarify my question. Assuming my first dive is a boat dive and I don't know how much weight to use. (I have some idea based on my intro dive from last year). Do I add or subtract weights once I get in the water? That's more the question I am looking to answer.
Thanks.ut:

 

[Charlie99]

adjuster-jd once bubbled...
Ok, maybe I should clarify my question. Assuming my first dive is a boat dive and I don't know how much weight to use. (I have some idea based on my intro dive from last year). Do I add or subtract weights once I get in the water? That's more the question I am looking to answer.
Thanks.ut:

Ummmmm. This is something you should discuss with your instructor. It will be much clearer after your OW class.

If you can't descend, you add weight. If you sink like a rock, or have to add a lot of air to your BC to stay on the surface, then you remove some weight.

The air in the common AL80 tank weighs about 5.5 pounds, so your tank will be about 5 pounds lighter at the end of the dive. Your wetsuit will compress and lose buoyancy as you descend.... particularly in the first 10 or 15'.
These 2 effects partially cancel out while at the surface with a full tank.

A common "rule of thumb" is that you adjust your weighting so that, with a full tank and with a normal breath, you float around eye level. A vigorous exhale should start you descending, provided you don't unconsciously fin yourself back up (a common new diver problem, along with sucking in a big breath before trying to descend). Once you get 10 or 15' down, your wetsuit is compressed and you will have to add air to your BC to have neutral buoyancy.

Moving from fresh water to salt water means you need to add 6 or 8 pounds of lead. Putting on more wetsuit requires more lead.