Stare at me blankly. Odd as I just kept flashing the ok sign at him and they just stared back, no response no nothing. By all appearence everything looked normal. They just didn't seem to get it at that time. We were about 10' apart in 30' of water swimming along a wall. I rolled over and signaled ok, nothing , stopped swimming, signaled ok again , nothing, swam towards them signaled ok , nothing, started an accent signaled ok, nothing, hit 10' signaled ok got an ok back decended to 30' signaled ok, got one back and had an enjoyable rest of a dive. Afterwards he asked what was wrong? I do not dive with him alone anymore.
My habit is, if we make eye contact I am going to give you an ok signal, don't care we did this 10 seconds ago,this drives my wife nuts, I don't necessarialy expect one back, but some form of acknowledgment is required. Most of the people I dive with are the same way. Probly started with nervous students or with my instructor when I was having issues.
How often do you communicate with your dive buddy under water?