There is never a total absence of visual reference. Tiny particles are always floating around you. Use them. Make use of the available options, there is never a situation where there are no options. You just need to find them.
cascas or Storker,
Sorry, just noticed this thanks to the above post.
Unless you tell me otherwise I think you guys above all seem to be ocean divers. Unless you tell me otherwise, I don't really think you appreciate how limited the vis is around here in some of these fresh water quarries.
Again... I really think you guys aren't getting the picture here. Muck diving around here (4 or 5 ft. vis this past weekend) doesn't afford you the luxury of projecting your straight line over objects between you and the final destination. A lot of the muck diving around here is like diving in a cloud or a fog that almost prevents you from seeing your buddy directly next to you.
Again, in REAL fresh water muck diving you have to keep your nose to the compass and keep the needle pointed the correct direction. Additionally, the bottom of some of these quarries around here have barren/lifeless bottoms or are covered in hydrilla. There's not really anything to focus on and swim to, even if you could see beyond a few feet in front of you. Sure there is floating particulate in the water, but there's no way to focus on one particular particle. There are thousands of them. Around here, saying to focus on a particle is like telling someone to focus on a water droplet while driving through a thick fog. Ain't gonna happen..
If one of you guys ever come to the DFW area, please contact me. We can go diving and you can show me how to swim from particle to particle..