OutCast is designed to be fairly water resistant. It is not waterproof, meaning if you drop it in the pool we get to sell you two! Seriously, the OutCast is built to be used and if left outside it will not sustain damage from the elements. Obviously it is not designed to be left outside permanently but it can handle weather issues quite well. Sprinklers, dogs, rain, snow, sleet and hail will not keep it from its appointed duty of sounding good. What you should keep in mind is that it is a high quality device and it does need to be recharged. Even though it's finish includes ultra-violet protection from the sun, It is best left in a sheltered location when not in use. If properly maintained it will give you many years of excellent service.
With respect to "beach wear", the unit should not be buried in the sand. Sand is no more an enemy of the OutCast than water, however care should still be taken.