Ballast change from 50F to 80F water?

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Brett Hatch

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Hi SB friends. I'm new to this forum -- have lurked for a year or so, finally started posting this week.

I live near Monterey, California, and all of my diving so far has been in that area. The water is pretty cold. Coldest water temp I have recorded is 46F, warmest 59F, air temps around 45-75F. I'm going to Bonaire for a week in February, and am trying to figure out whether to pick up any new gear in the mean time. Water temps there are 78-80F, with air temps just a bit warmer.

Here are my and my cold water rig's specs:
  • 5'11", 165lbs
  • Not a wimp, not a superhero with respect to cold -- some people only dive dry here, others dive slightly thinner and/or leakier wetsuits
  • Diving wet (for now) in an 8/7mm semidry with integrated hood (Aqualung SolAfx in medium-large-long size). Unsure of buoyancy, have not had a chance to measure
  • DGX pocket shorts, 2mm neoprene: maybe +1lb buoyant
  • 5mm Waterproof gloves, 5mm Deep6 rock booties: maybe +1 lb buoyant
  • Faber F7 high pressure steel 100 cu ft cylinder: approx -2lb buoyant at 500 psi
  • Standard 6lb SS backplate: approx -5lbs buoyant
  • Standard 1st stage + SPG + rubber longhose primary + necklace secondary reg setup from Deep 6: perhaps -2lbs buoyant
  • 2x small LED flashlights, DSMB with stainless spool, shears, knife, computer, extra double-enders, etc: maybe -1lbs buoyant altogether
  • Rubber MAKO dive belt with 4x 2lb lead pinch weights: approx -7lb buoyant
  • Deep6 Eddy fins: neutrally buoyant
  • Standard 2" nylon webbing w/ crotch strap
  • 32lb wing: OMS Performance Mono
  • No STA
With this setup, I am able to sink by dumping both wing and lungs on a full tank, and am able to hold a 15' safety stop without sculling with an empty wing and a near-empty tank. Seems to tick the balanced rig boxes. Doing the math here, all the hard gear adds up to -17lbs buoyancy. To me, this implies that all the neoprene gear combined must be pretty close to +17lbs buoyant at 15 feet depth.

I plan to do repetitive dives every day while I'm there, maybe ~30 dives over 7 days and nights. It's my understanding that exposure gear runs the gamut from nothing to 3mm shorties to 5mm full wetsuits with a hood. Never having dove warm water, I don't really know where on that spectrum I will fall, and figure it will take some experimentation to find the Goldilocks gear for me.

The questions I have are:
  • Is it likely that I will be over-weighted with my own rig and rented AL 80 tank, but no lead?
  • If so, it seems like I should pick up an aluminum plate. But if not, is there any upside to an aluminum plate anyway?
  • Is there any point to packing a weight belt and/or lead weights, or will I probably be OK with no lead?
  • If you dive a similar setup in similar cold water, what exposure suit do you pick in warm water, and what is the corresponding change in ballast?
Thanks everyone, dive safe out there,
- Brett
 
I dive a similar setup to you; 8/7 semi-dry, steel backplate, steel tank, 4 kg of lead. When I dive with the same setup and a 3 mm wetsuit, I don't need any extra lead to be neutral with an AL80 tank. YMMV of course.

You're going to love diving with less neoprene. You'll feel nimble.
 
The answer will always be to do a proper weight check wearing the setup you will use. Otherwise you are just guessing, Take a weigh belt so you have the option of adding weight. Don’t buy an aluminium plate, but consider getting a thin shorty to help preserve some warmth. Doing four dives a day will gradually make you colder despite the apparently warm water.

If you get in a fresh water pool without your suit do you sink uncontrollably or do you manage fine?
 
Cold and Wet steel tank thick wet suit
I am very close to the same weight as warm 3mm Alu tank.
+/- 2 lb
 
The answer will always be to do a proper weight check wearing the setup you will use. Otherwise you are just guessing, Take a weigh belt so you have the option of adding weight. Don’t buy an aluminium plate, but consider getting a thin shorty to help preserve some warmth. Doing four dives a day will gradually make you colder despite the apparently warm water.

If you get in a fresh water pool without your suit do you sink uncontrollably or do you manage fine?
Agree with this, with one minor modification. If you’re planning on making around 30 dives over the course of 7 days in 78 degree water, you might consider wearing a full body 3mm suit. This will help keep you warm and provide protection from any stingy things floating around. In warm water I also wear a thin hooded vest. Thus I only get stung on my hands and lips.

Aside from possibly considering obtaining a wetsuit, I see no reason for the OP to purchase any more gear for a one week trip, though he might wish to get a pair of tropical weight gloves if he insists on wearing any at all.
 
The water temp itself won't change anything.
The change in exposure protection is what is going to change everything. You will need something between nothing (fairly cold tolerant and shorter dives), a shorty (my first guess), 3mm full (second guess), and if you really want to be warm a 5mm full suit. Going with the middle choices there is a lot less suit than you use now in cold water. Yes, there will need to be changes in your weighting.

I would take a weight belt, but no weights. Just glancing at your specs you may be close without anything. Maybe need a few pounds. If you don't take a belt, you will need it. On the first dive do a weight check and adjust as needed. Whatever happens, it will be a lot less weight than what you dive at home.
 
5'11" 165?

Get yourself a 3mm. 12lbs will be more than enough with an al80 and an unbroken in wetsuit. Take off pounds as needed after a weight check at each dive's safety stop. I'd guess you will probably end up around 6 or 8 pounds..

oops.... didnt see the ss backplate.... so take off 5 lbs if u use that.
 
Hi @Brett Hatch

The water will likely feel quite warm to you and you are a young guy. Despite that, 4-5 dives/day will take the heat out of you. I wear a full 3mm when the water temp is in the 80s and added a 5/3 hooded vest last April when the water temp was 78. With a wetsuit something like this, an Al cylinder, and your current gear, I would imagine you will need between no weight to a few pounds. For me, the only good weight check is the safety stop with an empty tank. I would probably start with 2 or 3 pounds and adjust it on you first couple dives, you won't be far off, and then you will be perfect for the rest of the trip.

You'll love Bonaire, enjoy
 
OP, gloves not allowed in Bonaire. Your dive operator will supply lead, don't bring any. Your first dive in Bonaire is a mandated weight check.
 
Hi SB friends. I'm new to this forum -- have lurked for a year or so, finally started posting this week.

I live near Monterey, California, and all of my diving so far has been in that area. The water is pretty cold. Coldest water temp I have recorded is 46F, warmest 59F, air temps around 45-75F. I'm going to Bonaire for a week in February, and am trying to figure out whether to pick up any new gear in the mean time. Water temps there are 78-80F, with air temps just a bit warmer.

Here are my and my cold water rig's specs:
  • 5'11", 165lbs
  • Not a wimp, not a superhero with respect to cold -- some people only dive dry here, others dive slightly thinner and/or leakier wetsuits
  • Diving wet (for now) in an 8/7mm semidry with integrated hood (Aqualung SolAfx in medium-large-long size). Unsure of buoyancy, have not had a chance to measure
  • DGX pocket shorts, 2mm neoprene: maybe +1lb buoyant
  • 5mm Waterproof gloves, 5mm Deep6 rock booties: maybe +1 lb buoyant
  • Faber F7 high pressure steel 100 cu ft cylinder: approx -2lb buoyant at 500 psi
  • Standard 6lb SS backplate: approx -5lbs buoyant
  • Standard 1st stage + SPG + rubber longhose primary + necklace secondary reg setup from Deep 6: perhaps -2lbs buoyant
  • 2x small LED flashlights, DSMB with stainless spool, shears, knife, computer, extra double-enders, etc: maybe -1lbs buoyant altogether
  • Rubber MAKO dive belt with 4x 2lb lead pinch weights: approx -7lb buoyant
  • Deep6 Eddy fins: neutrally buoyant
  • Standard 2" nylon webbing w/ crotch strap
  • 32lb wing: OMS Performance Mono
  • No STA
With this setup, I am able to sink by dumping both wing and lungs on a full tank, and am able to hold a 15' safety stop without sculling with an empty wing and a near-empty tank. Seems to tick the balanced rig boxes. Doing the math here, all the hard gear adds up to -17lbs buoyancy. To me, this implies that all the neoprene gear combined must be pretty close to +17lbs buoyant at 15 feet depth.

I plan to do repetitive dives every day while I'm there, maybe ~30 dives over 7 days and nights. It's my understanding that exposure gear runs the gamut from nothing to 3mm shorties to 5mm full wetsuits with a hood. Never having dove warm water, I don't really know where on that spectrum I will fall, and figure it will take some experimentation to find the Goldilocks gear for me.

The questions I have are:
  • Is it likely that I will be over-weighted with my own rig and rented AL 80 tank, but no lead?
  • If so, it seems like I should pick up an aluminum plate. But if not, is there any upside to an aluminum plate anyway?
  • Is there any point to packing a weight belt and/or lead weights, or will I probably be OK with no lead?
  • If you dive a similar setup in similar cold water, what exposure suit do you pick in warm water, and what is the corresponding change in ballast?
Thanks everyone, dive safe out there,
- Brett

Brett...

Forget the math...far to many variables...rent a 3AL80 and in the shallows...preferably with with assistance...practise your buoyancy protocols...just as you did during your OW training...start with the lightest ballast first...

You should have your buoyancy dialed in within five minutes...during your drill...make sure you avoid any areas of surge/wave/current...and that you have sufficient depth...

Remember...any change in your kit configuration will affect your buoyancy...especially thickness of your exposure protection...I follow North Carolina crew style for warm water exposure protection...bathing trunks...Carhartt bib overalls...under a long sleeve rash-guard...I also pack a 3mm shorty...on the odd chance the local water is a little chilly...worn over the bathing trunks...under the overalls and rash-guard...

I certainly would not pack ballast...vacation operators will have lots...contact the operator ahead of time...ask all the questions...be prepared...don't over-think this...and avoid spending money on any gear that you'll never use again...

W.W...
 

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