If anyone is still interested, after much trial and tribulation, I finally got my Helix installed. I'll summarize here to help anyone else who might attempt this.
The Tackle: I have the 4 foot long, 8 inch disc Helix model # H0848. Used a 3/8" high grade (G70) galvanized chain that was on sale at WM for my bottom chain. (first photo)
The Setup: Found out that a 1/2" shackle opening will not fit over the 1" thick eye on the Helix. So the smallest shackle that you can use is a 5/8". However, the pin from the 5/8" shackle will not fit through the link in the 3/8" chain. So I ended up connecting the 5/8" shackle to the Helix, then connecting a 1/2" shackle to the 5/8" shackle, then connecting the 1/2" shackle to the 3/8" chain. (second photo) Got all that? I mail-ordered Crosby Shackles instead of the cheap Chinese crap that everyone around here sells. I suppose you could use a larger bottom chain which the 5/8" shackle pin would fit, then you would only need one shackle.
Used a 5' long 3/4" iron pipe that I had lying around as leverage for screwing the Helix. (third photo)
Attached the 1/2" shackle to the end of the bottom chain and moused it. Attach the 5/8" shackle to the 1/2" shackle
but do not tighten or mouse it. You'll need to take it off again on the bottom when attaching the chain to the Helix. (4th photo)
Dive #1: I did this in two dives because my shackles hadn't arrived yet and it was D-day (weekend off) for the install. I won't go into the diving details except to say make sure you have enough ballast to keep you on the bottom while working, and that moron idiot Maryland ******** boaters have no idea what a dive flag means
I can't tell you how many times I was buzzed by some inbred 3rd grade dropout with their 15 Honey Boo Boo family members in a 12ft boat out tubing and when you surface to wave them off they just wave back at you with their 3-tooth grin and come even closer to see what you're doing. Sorry, I'm a tad peeved.
Anyhoo, I swam out with the Helix and 5' turning bar to my desired location. Floating them out on a raft is helpful. I used my water toy raft that has a tough cover on it. I anchored this with a small anchor and attached my dive flag to a pendant buoy nearby. Going down about 10 feet I found a muddy clay type bottom. Using the bar I turned the Helix into the bottom. It went in easily, but with satisfying resistance. I did not hit any rocks (thank goodness). The only difficulty that I had was fighting the tide and that I didn't have enough ballast and kept trying to float to the surface. I actually held myself down with the Helix and the bar. I eventually got it turned all the way down so the eye was at "ground level", even a little below (as recommended).
I had put a small float and some 1/4" line in my BCD pocket to attach to the Helix eye to mark the location and I now tied this onto the eye. If you don't mark the location, and you have to come up for anything, you will NEVER find it again. That Helix eye on the bottom is like the proverbial needle-in-a-haystack. Once topside again, I tied a larger crab-pot float on the marker line. Oh, and don't forget your iron pipe. That's the end of dive #1.
Sorry, no pictures of the dive, but put a brown paper bag over your head and that is exactly what you will see in the Chesapeake Bay. Everything you do is done by touch, visibility is about 6 inches in the bay. (to be continued)