Last week, I was on a dive with a buddy of mine. Nothing too demanding. Depth was around 55'. At the surface, we agreed to descend along the anchor line, where I would make sure it was secure, but not going to be a problem to retrieve. I would adjust as necessary, then we would dive. This is fairly standard when I dive off my anchored boat, so nothing unusual.
Anyway, when we got down, my buddy gave the thumbs up signal. I don't know why, but I had a feeling it wasn't equipment, but more anxiety. Maybe the look in his eyes clued me in. Since we were close, I pointed toward the anchor line so he could ascend with his hand on the line as needed. When we got to Safety Stop depth, I signaled to level off, and asked if he was OK. He shook that off, and gave the thumbs up. That was clear enough that we should proceed directly up.