WIll a Couple have fun on a Disney Wedding Cruise?

Our son is is having a wedding ceremony on Disney's private island.He has booked the 4 night cruise on the Disney Wonder.They will already have been married by a justice of the peace before boarding He has invited mostly young adults and a few senior couples. My husband and I are not big Disney fans nor are the other couples in our age bracket who are coming. We were wondering what there is to do. We have cruised on much larger ships before. I am prone to sea sickness also. Should we reconsider even going on this cruise.Perhaps we could meet them in Florida the day of the actual marriage.? I am at a point where I would rather give them a check for $2,000 and have a small reception for them when they return from their honeymoon. We are really in a quandary over this. Any suggestions would be appreciated!