Sand, in large quantities such as at the beach, can be a great natural light reflector. Large hats can be great for flagging or blocking the light. With a high sun lighting the sand and a wide-brimmed hat shading the entire body, nice portrait lighting is readily available.
The Canon EF 70-200mm f/4L IS II USM Lens is a great beach portrait lens. The focal lengths this lens offers naturally push the photographer to the ideal focus distances for pleasing portrait perspectives. They are also narrow enough to eliminate the distractions commonly found on beaches.