Non-slip rubber tip arms
Hydrophobic coating - water repellent
Easily removable head strap
The Mentawai surf sunglasses look super-cool, work great on land, and are perfect for men and women. They are what I normaly wear when I am not surfing. These glasses make a great gift, because even if the person doesn't like them for surfing, they will still certainly be used on land. They are highly recommended as fishing sunglasses too!
One problem with these glasses in terms of surfability is that the frame is not padded and it rests on the nose. Officially, if you end up face-planting a wall of water hard, there is the potential for ending up with a very sore (read 'broken') nose. I have never even come close to having this happen when surfing in these glasses (or any others for that matter). However, you have been warned!