Worried about weight & wetsuit choice with Aldora's steel tanks

[anchochile]

Trying to sort through a bit of a conundrum. I'm hoping to make it out to Coz in early or mid June. I have always used Aldora in the past, but here's the problem: I dive a steel backplate, and am worried I will be drastically overweighted with their steel tanks. My past trips have been in the winter and I've worn a 5mm suit (necessary for me on those looooong dives in 79-80 degree water), and did not need any additional lead with their HP120 tanks, and was possibly a tad overweighted in this scenario.

In June I would probably want to wear a 3mm, but without that extra buoyancy of the 5mm suit I'm worried I would be way too negative and diving would be unnecessarily difficult.

So the options are:

1. Use my BP/W and a 3mm and just deal with being overweighted
2. Use my BP/W and a 5mm and hope it's not a ridiculous wetsuit choice for June in Cozumel
3. Rent a BCD to eliminate the issue (downside - I have my trim & accessories totally dialed in with my BPW have not used a traditional BCD since my training 100 dives ago)

What are typical water temps in early and mid June? If I was happy in a 5mm in February, would I be crazy to use it in June?

 

[boulderjohn]

In the worst case scenario you describe, you would be a few pounds overweighted with the 3mm suit and steel backplate. As an instructor working with students in a pool, I was regularly 6 pounds overweighted so that I could descend more rapidly if I needed to in case of a problem. I had no trouble diving with that extra weight. I used to do a buoyancy demonstration for my students in which I went from the bottom of the pool (12 feet) to the surface and back down to the bottom using nothing but my breathing to change and control my depth. It was easy, and, again, that was 6 pounds overweighted, and at altitude. (Yes, altitude does make a difference in buoyancy.)

I used to dive in Cozumel in June regularly, although it has been years since I have done that. When I did, water temperatures were around 81-82. For the first few years, I used a 0.5mm skin. In the last few years, I used a 3mm suit.

 

[Manatee Diver]

Random thought, why not get an aluminum plate? Those are typically less than $100.

 

[inquis]

Hopefully you know how much lead you need with an AL80 as a baseline. Much depends on what kind of HP120 cylinders they have. If they're actually Faber HP120s, they are over 7 lbs negative empty (almost 12 lb change from an AL80). If they are Faber FX120s at -0.7 lb empty (about 5 lb change from AL80), you may be golden.

 

[anchochile]

Random thought, why not get an aluminum plate? Those are typically less than $100.

I'll do that one of these days but I'm not going to be able to get a new plate and set up a fully new BP/W rig with harness, D-rings, buckles, etc before this trip. But yes, this would be technically the correct answer if I could make it happen.

 

[anchochile]

Hopefully you know how much lead you need with an AL80 as a baseline. Much depends on what kind of HP120 cylinders they have. If they're actually Faber HP120s, they are over 7 lbs negative empty (almost 12 lb change from an AL80). If they are Faber FX120s at -0.7 lb empty (about 5 lb change from AL80), you may be golden.

With AL80 and 3mm suit, I use zero lead. I'm not sure of the buoyancy specs on Aldora's tanks, although from my last trip I remember they had 2 different types (Faber & Worthington?) and they told me one of them was about 2lbs more negative than the other.

 

[Ian Fatzinger]

Honestly not bad to just wear the 5mm. No extra money spent and you'll nice and warm. I'm wearing my drysuit there in June for a tec course haha

 

[inquis]

It's also pretty easy to cool down a 5mm.

 

[anchochile]

It's also pretty easy to cool down a 5mm.

True, but I guess if I pee in it I might get heatstroke?

 

[inquis]

from my last trip I remember they had 2 different types (Faber & Worthington?)

It's likely to be the FX, then. Worthington has versions at -2 empty.

Based on the swing from an AL80 with 0 lead, you'd probably be 5-7 lb heavy in the 3mm.

Personally, I'd use the 5mm since you have it. Or take both if you have room.