The issue is sleep, your brain can only go so long without some kind of sleep and it stops performing well after a certain point. There has been all kinds of research done on this.

The adventure teams are all about when to sleep and for how long, the ones that win take less naps than those that lose. The solo ocean racers can take naps below and have the boat on autopilot, so thats not a good comparison. Even they have to manage their sleep patterns and the sleep/wake cycle is a big part of doing a long distance ocean race solo.

The issue on a beachcat is that grabbing some sleep is going to be difficult.

The question that you need to figure out is the crew rotation, and how to get all 3 guys enough rest to do a non stop 1000 mile race.

http://www.scientificamerican.com/article.cfm?id=how-long-can-humans-stay