The weather could change, but my guess is that they just don't like to cancel 2 days out. I've had each of the popular Morehead/Beaufort ops call me in the past on the night before and say 'Don't bother coming down'.
As far as dive operators taking people out in questionable conditions: All dive ops will cancel a trip long before it is unsafe for the boat to be out there. It's just not comfortable for anyone (crew included) and they want you to have a good time. There are some days when seas are up and the trip out is not much fun, but the diving can be fantastic. If you are not in good physical shape, or you are not used to getting on and off the boat, then you can have serious problems. Other divers, on the same boat, could have a terrific time. So, I guess it depends to some degree on the skill of the divers.
I don't think any of the dive operators take people out when conditions are unsafe for everyone on the boat, but some trips do run when an unprepared diver could get themselves in trouble. It's up to you to decide if you are up for it. Most dive ops err on the side of caution.
As far as dive operators taking people out in questionable conditions: All dive ops will cancel a trip long before it is unsafe for the boat to be out there. It's just not comfortable for anyone (crew included) and they want you to have a good time. There are some days when seas are up and the trip out is not much fun, but the diving can be fantastic. If you are not in good physical shape, or you are not used to getting on and off the boat, then you can have serious problems. Other divers, on the same boat, could have a terrific time. So, I guess it depends to some degree on the skill of the divers.
I don't think any of the dive operators take people out when conditions are unsafe for everyone on the boat, but some trips do run when an unprepared diver could get themselves in trouble. It's up to you to decide if you are up for it. Most dive ops err on the side of caution.