I wish I had some of the diving experiences that some of you have reported - it really sounds great and sometimes a little too exciting/adventurous for me!
When boat diving in the Puget Sound/Hood Canal of Washington, it is not uncommon to be dropped off to freely descend - this means that you must be able to ascend without a line. I always thought that this was normal. You watch your gauges (I was originally taught "watch your bubbles"), kicking up slowly/letting air out of your BCD, and not using the BCD as an elevator.
I was diving wrecks in the Red Sea and there was no line to go up and down and this was blue beautifully clear water - it can be very disorienting to some. The Instructor/DM guides would make a big deal about this, but personally, my son and I had no problems maintaining buoyancy in this water. It was wonderful swimming through open water where you could not see the bottom or the surface, just your gauges, including your compass!
Today on South Jetty/Newport, Oregon - I was only at 36 feet (12 meters) in murky water and I wanted to come to the surface to see where I was. I actually "knew" where I was (underwater wise) because I had done this dive many times before, but I wanted to see, for fun, from the surface. There were tidal currents and surge and no visual references after I left the bottom. I watched my gauges going up.
On open ocean dives in my area, the custom is to be dropped off the boat on top of a pinnacle. There is no line left down and the boat is not anchored, so you come up yourself from about 50 to 100 feet. You must have good buoyancy control and watch your gauges. When you surface, the boat comes and picks you up. You might have to blow up your SMB (or sausage) when you reach the surface to make sure the boat crew sees you.
The skill of ascending without visual references was taught to me in my beginning classes years ago. I thought everybody was taught this. Maybe this is a "must" that is only taught/emphasized in the murky waters of the Pacific Northwest.
Going up and down an anchor line or following the sloping bottom on a shore dive is great, but not available on many of our dives.
Heavy tidal currents and surge is common in our diving, but I have never had to deal with the excitement of hanging onto an anchor line and looking like a flag in the open ocean, like some of your described on your wreck dives. I would definitely want a marine radio and/or EPIRB in a water tight container!
Also, deploying a "sausage" and line is a great skill and is fun to do. I have never used one to orient my ascent rate, but more likely to mark a position of a found object or myself. Sometimes they can attract boat traffic, so one must be careful.
Regarding boat traffic, we were taught to freely ascend to our safety stop and then listen very carefully and ascend very carefully (not using BCD as an elevator), kicking to the top, being ready to dive down if necessary (this wasn't so much emphasized, but imagined from "Sea Hunt"
), and inflating your BCD only after surfacing.
Again, I read this thread with interest and was surprised at, what sounded like, how few were trained to do ascents without visual references. I guess this is a necessary skill in the cold murky waters of the Pacific Northwest and a tribute to my instructors at ESDS (Thank you Ron, John, and Ed).
