Use a 'runner' whenever possible - especially when you have smaller children in tow...
examples....
After the 'boat drill' - one parent can usher the kids upstairs to stake out a spot for the sailaway party while the 'runner' takes all of the life vests back to the cabin.
Other opportunities would be with the buffet lines -- one person can make a sampler tray and just stack empty plates underneath. Add extra silverware and head to the family either at the table or in the cabin... Even if you had to make two trips, the errand is 10 times faster without little ones scrambling around....it just is.