Jackson Blue conditions?

[diverdarren]

Anyone been to JB lately? Thinking of going next week.

[victorzamora]

I don't think it really ever changes. Quite a bit of flow, quite a bit of viz, 69F water.

[bamafan]

I agree with Victor on this. The flow in JB changes with the amount of rain we have been receiving. With more rain there is generally more flow. If the flow gets high enough the viz can get a little milky with maybe 30' of viz. This I believe is due mainly to sand / silt moving around in the back of JB due to the increase in flow. It seems to be more noticeable after a drought. Now if some farmer decides to fill in a sinkhole upstream you can have problems too. Generally all the caves on the Mill Pond are not affected by the rain / river levels that much. The viz in the shallower tunnels of Hole is generally better in the summer. The deeper tunnels such as the Century Tunnel and Consolation Corridor are clear. My theory on this is the water temperature of the Mill Pond water. As we all know hot water rises and cold water sinks. I think during the winter the Pond water is cooler than the spring water and you get intrusion from it and some sinkholes such as the one down by Day Loop road. If you are planning a trip and are worried about what conditions will be the Mill Pond is as safe as it gets in my opinion.

[Rhino]

Only dove JB last week and vis was at least 70' to the second T. Flow was less than the "new normal," or less than rip-roaring, but more than about 2-3 years ago when I believe it was generally considered a low flow cave.

[Sludge]

I've seen the flow down every now and then, but I've never heard JB being called a "low flow cave."

[Rhino]

I've seen the flow down every now and then, but I've never heard JB being called a "low flow cave."

My how time flies! Checked my sidemount cert., and it was 3-4 yr. ago when I started diving JB, and heard it was a low flow cave. Mostly heard that from 2-3 instructors, but also from a couple of new buddies, and especially before my first time in Madison - which was described by comparison as having flow. Of course, I wasn't cave-diving 10 or more years ago when the flow in JB was typically comparable or greater than it is on any given day these days.

[RN]

I agree with Victor on this. The flow in JB changes with the amount of rain we have been receiving. With more rain there is generally more flow. If the flow gets high enough the viz can get a little milky with maybe 30' of viz. This I believe is due mainly to sand / silt moving around in the back of JB due to the increase in flow. It seems to be more noticeable after a drought. Now if some farmer decides to fill in a sinkhole upstream you can have problems too. Generally all the caves on the Mill Pond are not affected by the rain / river levels that much. The viz in the shallower tunnels of Hole is generally better in the summer. The deeper tunnels such as the Century Tunnel and Consolation Corridor are clear. My theory on this is the water temperature of the Mill Pond water. As we all know hot water rises and cold water sinks. I think during the winter the Pond water is cooler than the spring water and you get intrusion from it and some sinkholes such as the one down by Day Loop road. If you are planning a trip and are worried about what conditions will be the Mill Pond is as safe as it gets in my opinion.

The JB flow does change with rain. When I first started diving it the flow was pretty low. In fact, it was almost non-existent. I remember doing a single stage swim dive to Stage Rock back then. A couple weeks later we had 20 some inches of rain in about 36 hours and everything changed. The flow increased dramatically. First, JB blew out. Yes, literally blew out. There was only about 5-8' of visibility that Saturday. By Sunday it had cleared up to 40' or so. A few days later it was back to normal except flow was ripping. It was the highest I had ever seen it. This happened almost 6 years ago in 2009.

https://www.youtube.com/watch?v=FObq6ZQ15MI

We've had decent rain every year since then and the flow has remained, although not as bad.

As for Hole in the Wall, my theory is conditions there are more affected by the Indian Springs golf course than by rain intrusion in the sink hole or the other entrance. The golf course has to start pumping more fertilizer into the greens and fairways in the winter to keep it looking nice and that all affects the visibility in Hole. This is especially apparent in certain areas of Hole and looking at the overlay in comparison to those areas and the golf course, they are pretty close. Of course, this could be affects of what they did 17 years ago. I'm not sure how the seepage works and if it is close to 17 years on the mark or varies by a few months. But I have also seen Hole run crystal clear throughout the year and have bad visibility during the summer. So it probably varies.

[TracyN]

Sink hole? Other entrance?

[Draker]

Sink hole? Other entrance?

Nothing to see here. Please move along.

[Scuba Al]

Dove JB yesterday (10/8) flow was down from when I last dove it back in Jan. swam back to around 2800ft before turning. First dove JB back in 2009 if memory serves. Then flow was down, not knowing any better returning the following years to find it back up.
FYI also dove Ginnie and the flow there also seemed down to me.

Al