Scott,
PM me with your email so I can send you my thoughts on the trip. Cutting the trip shorter makes it more of a boat ride than a fishing, surfing and relaxing trip.
There is another alternative for your crew member. He could get a new wife.
Having an “I absolutely must be home” time limit on a trip like this is tough. Mother nature may tell you that the trip is going to take a few days longer than you anticipated and I don't like arguing with her.