Touch contact navigation procedures in low-zero viz

[aquacat8]

If you can locate a deep spot, maybe this would help: Recently, in a low viz freedive at Warm Mineral Springs, I made a descent/ascent line with glow-in-the dark rope found cheap at Home Depot, weighted with a block of lead weight and hung off a float. I marked it every two feet with red paint. One could also tie knots to be counted. It was highly visible.

Easier to handle without knots though as you can chain it.

 

[-JD-]

I’m loving watching how this helpful thread unfolds... Divers helping divers, Scubaboard at it’s best. I was wondering, what about a fishing boat depth gauge on a kayak or float or something. Do they even make portable depth gauges like that?

Its been an incredible community. I don't think I have ever either started or commented on a thread and not come out the other end either learning one or many things or at least getting great ideas from those with more experience. Depth finder would be awesome. I have never seen a kayak in there but I think they allow it. Talk about making things even easier.

Actually @lowviz has been working on this concept in an attempt to dive/map a mountaintop glacial lake near the Delaware Water Gap in NJ. Maybe he will pop back in with some suggestions, but you may want to peruse some of the latter parts of this thread to get a sense of his GPS-enabled depth-finder setup: Sunfish Pond - dont let a boy do a man's job

You could, of course, go old-school and do soundings with a weighted line.

 

[Landlocked123]

I have a design for a floating tow-able s hotline assembly. PVC structure (raft looking 3x3) - would generate roughly 27 lbs of lift and be able to deploy a 10 lb weight via shotline. ...Petzel Grigri backfitted to a large spool. Netting on top of raft structure for containing rope in a safe way. Manual crank mechanism along with Grigri to capture progress on the way back and allow SLOW deployment so not as to take out any divers below ...I am sure a 10 lb weight to the head would not make me any friends. Gonna find out this weekend if they will allow it. It would be deployed 2 football fields away from the platforms and students in a safe and controlled manner. If they allow it I am going to build it.

 

[Landlocked123]

JD lets connect outside of this post as I am definitely interested in seeing this. I am on FB. Send me a friend request. George Vannet

 

[aquacat8]

Here is 50 feet of marked line reduced to 12 feet of chained line. It was wrapped around a pool noodle used as a float with a little dry bag for additional buoyancy but two noodles might have been better as easier to roll. To release from the surface undo the knot by the weight and unchain, unrolling pool noodle. To recollect from the surface just recrochet the chain and roll onto pool noodle. This easy technique is used by freedivers handling line. I don’t see why a plumb line could not be done this way floating over likely spots on the surface.

But your device sounds cooler, if less simple!

 

[aquacat8]

 

[Landlocked123]

Thanks for sharing definitely gets the job done

 

[lowviz]

My progress stopped due to a serious cervical radiculopathy combined with a rotator cuff tear. Dominant arm, of course. On the mend, but stupidly slow...

If you guys dive Sunfish Pond please post what you find. Our loose-knit 'team' is all about sharing.

Depth sounding. Tried it with a plumb-bob and Dyneema line. Problem is, I was in an inflatable raft and the wind up there was constantly blowing me all over the place. The line was always well off vertical, more of a dragging anchor than a depth sounding line. I then bought a GPS/Depth finder combo. The plan is to just traverse the pond snagging GPS coordinates. Found a way to make a square grid of lat/long coordinates that cover the pond, turned out to be quite a math chore. Anyway, once I hit them all from the surface (doesn't matter how I get from one to the other) the software promises to make a topo map for us.

The bottom (in several large areas) is a dense mat of cord-like aquatic growth. If you dive it, bring a bit back so it can be identified.

Good Luck on your dive attempt! Take pix.

 

[aquacat8]

Hope you feel better soon @lowviz !

 

[Landlocked123]

Yeah hope for a speedy recovery for you. My dive buddy is in Mexico for 2 weeks of diving. When he gets back we will have 2 weekends to take some other cracks at it. After that he is going to do his intro to tec class with John Chatterton of all people. I will post any updates if we have them.