NuName,
I agree that it can be a bit irritating receiving applications from those who do not meet the experience requirements that one may seek, but a post such as yours will never stop it happening, especially when the employment market is as it is now.
If you made it clear in your advert that only those meeting your criteria will be considered, then you have two options; either ignore those who you feel are wasting your time, or have a standard email reply stating "sorry, you do not meet the advertised requirements, so can not be considered for the vacancy."
It may be a minor inconvenience, but is it such a big deal? Are you advertising for crew every month? I suspect not. The time spent here posting on the topic could have been better spent writing "thanks, but no thanks" to the unfortunate hopefuls who are perhaps desperate to find their first job.