She's right - there are a couple of high class resorts that require long 
pants and a collared shirt but we can easily avoid those.  The first few 
years we went sailing down there I always took long pants and even a sport 
coat "just in case."  The sport coat NEVER got used.  I usually wear a pair 
of khakis on the plane since they are sometimes cold and have used them a 
couple of times down there over the years but for the most part it's a tres 
casual part of the world.