Catering to an island destination

I run the catering department attached to a brewery.  At times I am assigned events that if I had my way, I would not necessarily agree to cater.  In this case:

175 people

Island wedding - about 2 hours drive from my kitchen to the ferry, ferry ride is an hour, then another 45 minutes to the site.   Also, have to arrive early to the ferry landing because of limited space. 

The budget is miniscule: 3500 all inclusive (tax, grat, labor, food, delivery, ferry tickets, gas, plates, flatware, etc)

I've worked out a bare bones menu that I can prep ahead of time, keep cold until I cook it at the site (I have a profesional bbq, the site has two home ovens and electric ranges)

The dinner is a buffet, I can swing it with 8 staff members.  My main problem is transportation: With the ferry schedule, it'll be a 17-hour day for the staff.  I need to find some way to knock those 8 hours of  transportation down, while also reducing the cost for ferry tickets.

Any ideas? 

Tell me about it.  Friend of the owners; I'm kind of stuck catering it, but also magically not make the brewery lose money.  I'm trying to contact some of the restaurants on the island; maybe they have some employees that would like to pick up some extra hours and save me about $800 dollars. I can't think of another solution. I mean, it is entirely possible to to all of the kitchen with 2 people. I'd like at least 4 servers. Since it is a buffet and beverages are not table service, it wouldn't be too strenuous for them. I may be able to send all the equipment with the bar the day before to save time. I think getting labor from the island is my second best bet.  My first best bet would be to have them hire an island catering company.

Thank you all for your responses.  I presented the numbers. I suggested getting island residents to help with service to limit the drive to only 2 employees.  In the end, we ended up using minimal staff (6 ppl: 3 cooks (2 turned into servers for service) and 3 servers.  The bar was setup the day previous by the groomsmen :) as well as tables/chairs/settings.  We did the job, did it well, and logged 96 hours between 6 people, 37 of which were overtime hours.  Our net profit was $400. And we got paid to spend most of the day on a ferry. So while the individual employees were happy, the clients raving about everything, I came out happy but with more grey hairs.  Not something I'd like to repeat. 

This is something I'd normally not agree to cater, but assist them in finding the caterer right for their event.  In this case, the owner of the brewery was viewing it as a wedding present (and a nice one at that).

After we got on the ferry, I could start reducing my stress level.  The biggest hurdle after logistics was the yellow jackets around the carving station.  Yikes!