The OP brought this up because last weekend we were diving in literally 2' brown muddy vis and doing blue (actually, dark brown) water ascents. To be honest, we were doing such a great job, it even suprised us. At the 20', I was thinking of tossing an OOG at him, and just as I was about to, his light started waving and he did on one me, the dog. I don't think we moved more than an inch.
On the next one I shot a bag at, I think, 50'. Even just letting it hang there in front of me made the the ascent a lot easier in the bad vis. It's common for us to do zero reference switches.
We did all our deco's with the scooters off, until the last dive at a location that had 10' vis, then when we hit 20', we couldn't stand it anymore... it was too much fun zipping along the rocks and wall. On a tech 1 type dive, if you plug the numbers into whatever deco software you want, you're not going to see a significant difference in 20' to 10' during the final stop, so I don't have a problem scootering at that range should conditions permit.
But what Al said was correct. Our IANTD instructor didn't like doing brown water ascents with an obligation without shooting a bag. He thought that, if something went sideways, in the heat of things, it was too easy to lose control before you knew it. Still, we do these all the time, and throw things at each other on purpose (usually before 70' or after 20'), like valve drills, OOG or bottle hand-offs. We were discussing what the actual DIR take on this is.
On the next one I shot a bag at, I think, 50'. Even just letting it hang there in front of me made the the ascent a lot easier in the bad vis. It's common for us to do zero reference switches.
We did all our deco's with the scooters off, until the last dive at a location that had 10' vis, then when we hit 20', we couldn't stand it anymore... it was too much fun zipping along the rocks and wall. On a tech 1 type dive, if you plug the numbers into whatever deco software you want, you're not going to see a significant difference in 20' to 10' during the final stop, so I don't have a problem scootering at that range should conditions permit.
But what Al said was correct. Our IANTD instructor didn't like doing brown water ascents with an obligation without shooting a bag. He thought that, if something went sideways, in the heat of things, it was too easy to lose control before you knew it. Still, we do these all the time, and throw things at each other on purpose (usually before 70' or after 20'), like valve drills, OOG or bottle hand-offs. We were discussing what the actual DIR take on this is.