Eagles Nest Flow...

[karst2008]

Hi,

I have yet to dive Eagles nest as I just recently got trimix certified. I do however have a few questions that the people of the board might be able to help me with. Not its not dive planning.... its about the flow in the nest. By refering to the Upstream and downstream sides I'm assuming that the upstream is springing and the downstream is siphoning. Is this correct? What magnitude of flow have people experianced? What about the lockwood tunnel? Also, looking at the maps it is unclear about the end of the lines. Do they just pinch off in a section too small to continue, stop with more cave ahead, or end in a room with no possible leads (please list EOL upstream, EOL downstream, EOL lockwood).

Thanks in advance!!!!

[FW]

Very low, if any, flow.

[Walter Pickel]

As Forrest stated, there is little if any discernable flow. It is BIG cave so that serves to minimize discernability of the flow.

At some of the EOLs (upstream, downstream) it pinches down. At the Lockwood EOL it is a rubble pile -- it goes to a small bedding plane that more than likely leads to John's Pocket.

Since you are a new TRIMIX diver and new to the Nest I wouldn't think you'd be pushing EOLs on cave that averages ~260/~240.

The maps are "approximations".

[Mike Edmonston]

The only flow that I ever noticed was while decoing in the tube. You sometimes notice the colder water coming down with tidal changes.

Either that, or last week the team above me had terrible buoyancy

Just kidding guys (If you're reading this)

Cheers,

[OutlawCaver]

IMHO, any dive beyond the debris cone at The Nest is a very serious dive. I have a great deal of respect for the depths involved and the rate at which gas supplies diminish. Even if diving CCR technology you still have to plan for OC bailout at depth. My habit on OC is to never leave the cone with less than 300 CF of trimix gas on each diver, regardless of how far I plan on going up or downstream. Having never dived it CCR, although I plan to, I will have at least two 80AL or two 85 LP steel as BO.

[SuPrBuGmAn]

If you don't know how flow relates to upstream and downstream, perhaps you want to look into less advanced sites to gain some real experience in caves...?

[jj1987]

If you don't know how flow relates to upstream and downstream, perhaps you want to look into less advanced sites to gain some real experience in caves...?

OK, I'll bite...how the heck do you know which side of hole in the wall is "downstream" when last time I was there I could have sworn they were both springing?

[smaclean]

It used to be experience that you knew which way to go. Downstream hits a duckunder restriction at 200 feet. If you go the other way and hit 270 with no duck under that must be upstream. This was too complicated apparently so a wise diver put little signs at the debris cone pointing divers who didn't know better which way to go.

[Ben M]

OK, I'll bite...how the heck do you know which side of hole in the wall is "downstream" when last time I was there I could have sworn they were both springing?

The downstream line is tied off on the bottom (down) and the upstream line on the top (up) of their respective passages. I have no idea where their original names came from.

[cavediver27]

The downstream line is tied off on the bottom (down) and the upstream line on the top (up) of their respective passages. I have no idea where their original names came from.

Not sure what you described above because it makes no sense. This is the correct way to determine the direction:

When you drop down the line through the chimney you come to the 'T' located slightly to the side of the top of the debris cone. The line that goes DOWN the cone is the UPSTREAM line. The line that goes UP the towards the top of the cone is the DOWNSTREAM line. That is the correct method.

Simply put, you go "up" to go downstream and you go "down" to go upstream.

All I can say is there is a lot of mis-information posted about Eagles Nest from people who probably never actually dived it. As always, my suggestion is that if you never dived it before do the following:

1. Be full cave and at least hold an Abe Davis or Wakulla.

2. Hold advanced trimix certification and be very comfortable diving deep.

3. Find someone who has experience in the Nest and dive with them for your first couple of dives.

4. Plan your gas, overall dive plan and bailout tables with the experienced diver.

5. Turning on thirds is not necessarily the primary (or even the correct) turning factor, turning on time, which is often before thirds, is often the correct plan. At these depths, time is much more critical than at 95' in Ginnie.

6. Your safety reel should be a primary reel, not the typical safety reel. If you loose the line in the Nest you well need lots of line to find it again.

7. A few other thoughts:

a. Carry an extra mask in a pouch
b. Have at least 2 computers / bottom timers
c. Carry an extra primary light.

8. There's lots more but this reply is getting too long.

A final thought I need to say. When diving deep, especially in caves, time is critical. If you have a problem at depth and it takes 5 or 6 minutes to resolve it, your gas and deco obligations change dramatically. Those extra stressful minutes probably burned through a bunch of back gas and you've added about 30 minutes to your run time. When something goes bad deep.....you have very serious issues to deal with and hopefully you have the experience and training to resolve them and survive the dive.