A dive in my opinion is any time you use breathing apparatus underwater. I do not log pool dives and I don't log sticking my head in the bath to check a reg. I do not keep paper logs at all - I just download the data from my computer and fill in the site details and buddy name. If there is anything worthwhile adding, I can type notes into it and if I've taken photos, the software can find them from the time and date data and automatically attach them. If I need to show somebody my log book, I can show them the computer or export them to PDF and print them.
I can tell you exactly how many dives I have done but I have selected 'I just don't log dives' option for my SB profile. The reason for this is because I do not feel it is relevant. Say for instance a novice asks a question and gets two replies - one has 200 dives and is offering good advice and the second has 1,000 and is talking bollocks. The OP has no idea who is right, but which person are they more likely to trust?
There is a lad at my club, Alan, who did his OW in the UK in December 2011. The instructor introduced him to a few of us at the new year party and he was really buzzing from diving. I went along a fortnight later when he did his AOW and he had bought all the gear. We had a club trip to the sound of Mull, Scotland, coming up and he booked on it. It was a three day liveaboard on an old converted fishing boat and he hadn't been in the sea or deeper than 20 metres.
As he was so keen, a lot of people were happy to put in the effort to get him some time in the sea, so we organised a few days shore diving in Wales and got him in Dorothea (a very deep quarry) to get him experience of the 30 metres he was qualified too but had not yet dived to. Within about 25 dives, he had dived in crap vis, current and cold water.
He had also booked a Red Sea liveaboard a couple of months later organised by one of the instructors. Officially he had to have 50 dives to do it but it was getting close and he only had 40. He mentioned it to the instructor who told him not to worry - he knew the dive operator and he'd square it with them.
When they came back, I was talking to the instructor who was having a chuckle about him. On the boat, they had everyone sat around the table for their introductions. They had about half the spaces and the rest were mostly lone travellers and couples. Most had about 100 dives and then they got to Alan.
"How many dives have you logged, Alan?"
"Forty-two."
The dive operator looks concerned...
"We've got a bit of a problem here..."
The instructor then chips in,
"Let me assure you, none of the dives will be a problem for him..."
"I'm not sure...Alan, have you ever been on a liveaboard?"
"Yes."
"Where did you do that?"
"Scotland!"
"Ha ha! Welcome aboard Alan!"
We get people all the time coming for refresher courses. They have 100+ logged dives because they have done a liveaboard every year for five years. They don't dive for almost a year and then come for a tune-up in the pool so they can go again. Apparently there were many like them on this trip who were banging into the wreck and going up and down like a whore's knickers while Alan was hovering effortlessly over the wreck thinking 'This is easier than Scotland'.
I dived with a lad a while back. He was a trainee Divemaster and was completely f**king useless. He had been doing two 15 minute dives on a single fill, without even getting out of the water in between. He wanted to get signed off quickly so he could do the IDC and move abroad, working as an instructor. He is now an MSDT after doing some sort of crash course in Thailand. He is passing on his knowledge to novices and has only ever dived in benign training sites.
I appreciate it is difficult to gauge somebody's ability until they are in the water, but one would assume more dives equals more experience and therefore more ability. However, I reserve all judgement until I've dived with somebody. My first thoughts would always be the guy with 200 cold water dives is probably more experienced than the guy with 1,000 dives in a tropical paradise.