There are many clues to diver experience and competence that are evident when a diver comes on board the boat. The most obvious would be their C card and log book, howeverthe fact that they have either one of these may not accurately reflect what the guy is going to look like in the water, and I have dived with DM's and even instuctors who are absolute wrecks underwater, and who I would not feel very comfortable leaving unsupervised on more advanced dives.
The less obviious clues don't guarantee anything either, but they do offer up a little more information. I don't claim that any of these are right all of the time, but it has been my experience that:
1. People who talk endlessly about how great they are at diving usually don't dive well. People that are very good divers generally just sit back and relax and wait for their turn to jump in and do their thing.
2 Equipment selection and wear. People who have alot of new fangled gismos and whatever are usually newer divers. Older, more seasoned divers usually tend to favor a more simplified approach. Equipment wear can also tell you a good bit. A diver that unpacks a BCD, or wetsuit or regulator model that just came out last year which is all salty and faded and scuffed probably does a fair amount of diving. Conversely divers that unpack brand new looking gear that's ten years old, or divers that unpack a complete ensemble of brand new gear usually don't do alot of diving.
3. Questions that divers ask can give you alot of imformation about their experience, so can the kind of stuff they seem to be concerned with.
There's a ton of stuff like this, and I'm sorry, but I don't have very long to write about it right now, I'll check back in this thread later on, but there's one thing I'd like to add befroe I run. The most accurate assesment that you can make of a divers in water skills and experience is to jump in the water with them and actually watch them dive.
