scagrotto
Contributor
I told the instructors helping me that I must have a cold ... Can something as simple as a cold cause a dive experience to go suddenly awry like this, especially when I already had four successful dives?
First, you mention "the last two weekends"; two of those 4 dives were either the previous day or even the previous weekend. Either way, they aren't relevant to the situation. Also, the way you tell the story is that you told the instructors you must have a cold some time before you had really obvious symptoms. Colds don't just happen immediately so you could have had some early symptoms even if you weren't consciously aware that you were getting a cold and resultant congestion. Once you've got some congestion ear problems can definitely happen quickly if you go diving. It's also possible to dive and not have ear issues even though you're congested. That means it's certainly possible that the developing cold made you feel off before starting the 3rd dive, and it all seemed to happen very quickly.
Of course none of that guarantees that you weren't (also) having a problem with nerves. As Eric suggests, there could have been various issues going on, and they could have combined with a cold/congestion to cause multiple issues. I'll also ask if there's any chance that you didn't really have a cold? Were there symptoms beyond the problems with the ear? You can have ear problems as a result of issues with equalizing that are similar to congestion from a cold. Your ear(s) may feel "full" or blocked as a result. Whatever the cause, your problems at the beginning of the dive could certainly make it more likely that you'd have a problem with equalizing.
Your OW course may not have gone into a lot of detail, but there should definitely have been some mention of the possible problems of diving while you're congested. You certainly know a bit more about it now, but if you can't remember any discussion about it perhaps you still need to review the course information. Going back to the "last two weekends" bit, if you had one of the courses where everything happens in only two weekends it can be easy to be exposed to all the info but not retain it as well as with a course that's spread out over a longer period of time.I can't help but think it was psychological because a cold does not stop me from doing other things.