Madison Blue ''crosunder tunnel''

[Phil]

Hi,
Can anyone give me some info on that tunnel.
Does the begining is in the main room at the entrance of the cave?
Is it a dificult section of the cave?
I dont find any complete maps showing that section of the cave but I saw some details on the map that we can see at the park entrance.
What is the depth?

Thanks
Phil

[JCDdiver]

The entrance of the cross-under tunnel is at the beginning of the cave. I haven't dove it, I've only poked my head in there. It didn't look too bad. If my memory serves me right it's ~60ffw.

[bletso]

Be prepared to plow through some very heavy silt for about 20-30 feet. Sidemount for that distance would be better but not necessary depending on your experience and 0 vis comfort. (Very short distance. After that it is some beautiful and fragile cave. The line may be buried. It has been a long time since I dove it. The weir stops the natural flow of the cave and a silt mound builds up there.

If you enter via the "rabbit hole" its entrance is on your right and down though a large hole next to the wall.

Dale

[icestac]

I have poked around down there a few times. It is silty as hell down there in the beginning. There are a couple of lines in the first section and the correct one seems obvious now, but the first time I went down we took one to the left and ended up with a nice silt cloud as the cave seemed to pinch down. As of October the line to the right was definately buried in the silt mound as you head up that first hill.

[OFG-1]

It is not a big tunnel. Gerri and i have dove it back mount several times, expect some silt. There are places that you cant turn around for short distances, some bigger areas. I would say the average height is 4 feet or less, average width 6 feet as a guess. There uses to be a cable reel sitting in the entry room with a checkerboard nailed to the top of it, but I dont know if it is still there.

[w ripley]

When you dip down into the hole on the right under the large rock past the Rabbit Hole, it is the line that runs to the right. The first line you come to, the one that's on the left going in, only runs a short distance, maybe 200 feet, and ends. My map shows the Crossunder tunnel runs 950+/- feet to connect to the deeper tunnel that runs parallel to the paved main road. The Crossunder ends about where the bridge is on the main road.

With proper proofing and setup you can do a long circuit from the Rabbit Hole, to the Rocky Horror, to the Well, down the Bad Lands to the Crossunder and then back out. As previously mentioned, the first part of the Crossunder tends to get infilled with sand, so you want to be prepared to turn or abort the circuit dive if you do run into it.

It's a nice tunnel IMO, althought it does have a couple of silty spots on BM, going from 60 to 80+ feet deep, before dropping down into the deeper, parallel tunnel I've always called the Aquaduct, which is probably more accurately the downstream 3000+ foot section from the Crossunder.

The authority, IMO, is Wayne Kinard at Amigos Dive Center. Suggest you stop by and talk to him.

[Phil]

Thanks everyone.
I found the line but we had done a long dive before.
We will try it next time.

Phil

[gasdiver]

Where can one get the most current map of MB? Mine is so old, it does not have the Godzilla tunnel on it. The crossunder is on it, but it doesn't show much and ends in a question mark.

[mag3]

Where can one get the most current map of MB? Mine is so old, it does not have the Godzilla tunnel on it. The crossunder is on it, but it doesn't show much and ends in a question mark.

See Edd or Stacey at Cave Adventurers. The one I just bought from them is 2x4' and has a lot of detail. Beware, there is a smaller 11x17" version that is not the same. Edd/Stacey have the big one.