"but how do you choise the crew?? "
That's a personal call. You can (and I'd suggest should) first ask them for a sailing resume. Lots of folks will have one, listing years and who they crewed for, what they did, and so on. No gotz? Go type it up. Then you can ask for some references
(if the trip is "big" enough) or at least, references of reliability
. Got a driver's license
? Got a credit check? Or at least, own a checking account and credit card? A home address and telephone unmber? If they are crossing borders with you, they should be able to post their own bond, or return air ticket--whatever that next country will demand from your crew.
You can go with just your gut feeling, some people are pretty good at that. Or, you can be crueler and more objective, and go the line of asking for references and other "paper" that can be checked to find out who you are dealing with. If someone gets upset that you are going to leave photocopies of all IDs and passports with your float plan--that would be an indication that they don't want to be traced, and a fast "no way" for me.
A friend of mine is a small-scale landlord, rents, leases, sells lower-end private homes. He found out early in the game
that if he asked for a credit check--half would disappear. Half would agree--even if it came back lousy. But the ones who came back with a decent credit check (no bankruptcies, no late problems) tended to be people who took some responsibility about life. Yeah, there are always exceptions and reasons...but he stuck to the line, and his "problem tenants" practically disappeared after that. (He figured out, his gut feelings just weren't good enough for the size of the risks he was taking.)
On the easy side? Call a crew meeting interview for any specific date and time. The ones who show up ten minutes early, go to the top of the list. The ones who show up late? Hey, unless the ambulance driver says "He insisted we stop here before we could go to the hospital" [g] they go to the bottom of the list.
Not saying any of these are "MUST" criteria...but think along those lines, you'll find a set of criteria that work for you.