7mil in 70+ degree water? Is my instructor right?

[TMHeimer]

It's one of those "depends on your cold tolerance" questions. 7 mil for me would be overkill at those temps. Anything over 60F I will just wear the top of my 7 mil and adjust for the trim difference. My only other suit is a shorty. That would do me at 70F.

 

[jcrews5508]

TMHeimer is correct, it's all about tolerence, I forinstance wore a 3mil today in waters that got as low as 58. If you can tolerate it safely then go for it however I would trust your instructor being that its your first dive.

 

[pwr2al4]

One the most important lessons that I learned when I got my Master Diver cert way back when was what it was like to be truly freezing. It is a terrfing feeling of pain and just being constantly overwhelmed with cold. Thats literally the only think you can process from the second you get to depth until ascent. Just shivering the word freezing running through your mind 100mph. It taught me a very valuable lesson about what to expect if ever caught in that situation in a non semi-controlled environment. I couldn't work my equipment, had no situational awareness, no idea what my bottom time was at. etc.

 

[spectrum]

It's one of those "depends on your cold tolerance" questions. 7 mil for me would be overkill at those temps. Anything over 60F I will just wear the top of my 7 mil and adjust for the trim difference. My only other suit is a shorty. That would do me at 70F.

You appear to have exceptional cold tolerance.

 

[Blazinator]

I couldn't tell if this was mentioned or not, but what really makes a difference between most folks is how thick their natural "bioprene" is. Skinny divers generally need more neoprene, while girthier divers often do not.

 

[mfolsom]

I just went through this last weekend in a quarry that was 70 some above the thermocline and in the 50s below it. That quarry goes to 70 feet or so. I asked a similar question here and received the same variety of answers. I opted for the 7mm suit, hood, gloves and boots and was not uncomfortable in the water at any level. We had a walk in area and when I first put the gear on I went and got wet. That took care of the overheating while waiting to dive. You'll figure it out. Have fun and enjoy your dives.

Mark

 

[sjoliat]

I'm not aware of any quarry near Cols that has a depth of 35'. I don't know if they have access to a private quarry or if you are travelling to one of the bigger ones in nw OH. If it's Twin Quarries then the max depth is ~20' and the temps should be at least in the low 70s as mentioned above, but i can't imagine anything in the 35' range being warmer than the low 60s. Even if it is in the low 70s you'll be surprised at the difference between floating around on the surface and staying submerged for 30-40 min. Probably wont be too hot except for being out of the water in the sun.

 

[Kingpatzer]

You may find yourself just hanging around a platform and not doing a lot of moving for parts of your dives. After 15 minutes or so of not moving in 70* water, you might be surprised at how much body heat it is possible to lose.

Some people are fine in those conditions. MOST people are not. Your instructor is right to not trust your thoughts as you have no experience in this area and he does. You may well be one of the people who do not need that kind of thermal protection in those temperatures. But you might find that isn't the case either.

I tend to be warm when it's 50* outside, and I've been known to walk around in shorts in that weather. But I dive dry unless the water is above 80* or so. Water conducts heat much more efficiently than air, and certain common new diver behaviors, such as elevated breathing rate due to the excitement of the new experience, can further increase heat loss.

Enjoy the dive and do what your instructor recommends. If you find afterwards that you need less thermal protection, then use less when you dive after being certified. But for right now, trust your instructor -- her expertise and ability to keep you safe while you learn is why she's there.

 

[softballer]

I'm not aware of any quarry near Cols that has a depth of 35'. I don't know if they have access to a private quarry or if you are travelling to one of the bigger ones in nw OH. If it's Twin Quarries then the max depth is ~20' and the temps should be at least in the low 70s as mentioned above, but i can't imagine anything in the 35' range being warmer than the low 60s. Even if it is in the low 70s you'll be surprised at the difference between floating around on the surface and staying submerged for 30-40 min. Probably wont be too hot except for being out of the water in the sun.

Circleville Twin Quarries

 

[pnw_diver]

We are doing our checkout dives next Saturday/Sunday and he said we will be using 7mil suits. I had to go in and do a proper weight check in his 70+ degree pool and I literally FRIED.

I asked him if we could use thinner suits, at least a 5 mil and he said "I wear a thin suit because I don't get cold but you guys are wearing a 7 mil.

The quarry is currently around 70 degrees with another week to heat up - it's only 35ft and there is really no thermal change from top to bottom (according to instructor).

In my experience, it's going to vary a lot on an individual basis.

I have dove in water down to 42F actual in a 7mm (double layer over core) and been quite comfortable. I've also dove where the temp at depth was around 70F actual and been a little chilly in a 3mm shorty (the surface temp was 78F). During that same dive, my buddy who as wearing a 5mm full suit was cold. I have a layer of "natural insulation" so that makes a difference. I have more cold tolerance than the average diver, I think.

I dive primarily in Puget Sound, and I dive wet 100% of the time. The vast majority of divers I have seen dive dry in the same conditions.

Were it me, and the water temperature were truly 70F, I'd be wearing a 5mm.