Enough thermal?

[Kaneda13]

I'm looking at making my first venture into the Bonne Terra Mines next month, wondering if I've got enough thermal. I'm used to diving quarries, and the cooler water doesn't normally bother me. Dove 2 weekends ago in Logansport at 69F with just a 3mm long (no gloves nor hood), and was perfectly comfortable. I've picked up a full suit of Bare exowear, gloves, hoods, still working out boots. I'm wondering what anyones opinion who's dove 60F water is with a 3mm and thermals. My next jump is all the way up to a 7mm. I've never dove it (picked it up second hand), so I have no idea what my buoyancy with that would be. I normally dive fresh water with my backplate and no weights, in salt water I bring 4lbs with me. Thoughts?

 

[Whitrzac]

You need the 7mm for bonne terre, no question. Maybe even the base layer too,

I doubt they would let you dive with a 3mm.

 

[Dark Wolf]

Never been there. Based on another mine I dove regularly, I would also suggest the 7 mil.

DW

 

[Whitrzac]

Never been there. Based on another mine I dove regularly, I would also suggest the 7 mil.

DW

Was that mlm/the offsets or is there another one?

 

[Dark Wolf]

Was that mlm/the offsets or is there another one?

Oronogo circle mine.

DW

 

[Whitrzac]

Oronogo circle mine.

DW

Any overhead or just open pit quarry?

 

[Dark Wolf]

Any overhead or just open pit quarry?

Quite a bit of overhead. There was a cavern area, and a number of horizontal shafts. I think I have some pics from when the mine was in operation, let me check.

DW

 

[Subcooled]

I'm wondering what anyones opinion who's dove 60F water is with a 3mm and thermals.

I have been diving in swimming trunks in 64F but 60F is too cold. I'm sure you'll need a 3mm suit.
What's the length of the dive?
It'll be a cool dive, but it's OK I guess.
I'm sure more exact advice is available (see previous posts).

My next jump is all the way up to a 7mm. I've never dove it (picked it up second hand), so I have no idea what my buoyancy with that would be. I normally dive fresh water with my backplate and no weights, in salt water I bring 4lbs with me. Thoughts?

You'll need lots more with a 7mm suit. I need 4lbs for a freedive alone (no suit).
Are you carrying an aluminum tank or a steel tank? What capacity? Tanks affect buoyancy.
Let's assume you need 16 lbs. This is a rough guess, Wetsuit divers may correct me.

 

[Dark Wolf]

The above pic is of what would become the 4 Doors cavern area.

General mine operation.

I am not 100% sure, but this may be the deep shaft on the South side of the quarry. If it is, it is the shaft that contains an old locomotive about a mile in.

DW

 

[Subcooled]

Wonderfull pics!
A locomotive a mile in? Exciting!
A bit far though for open circuit diving (assuming no staged bottles).