If you really wanted to bump your logged dive count, you could fill your bath tub and "dive" in there. I wouldn't recommend that, but you could do it.
Basically, I only log dives where I feel I got something out of it....did I have a good time, did I learn something? If I got in the water, descended to find that the visibility was nothing (or the surge was uncomfortably strong), and exited the water within a couple minutes, I probably wouldn't log it. Now, if my buddy had a free flow and we had to share air on an ascent with the aforementioned dive, I probably would log it because it was out of the ordinary and I learned something from the dive.
It comes down to your criteria. If you want to count anything that's more than one minute, you can do that....if you want to log anything that's longer than 20 minutes, you can do that....it's up to you, but if you're working toward a certification that requires X number of logged dives, you should figure out what the agency counts as a dive.