Practical Advise From our Guides...

Snorkelling Mask

If you are using your favourite old mask, inspect the rubber carefully for cracks and signs of aging. You don't want a strap to break or a leak to suddenly appear while you are on your trip. If your are planning to buy new equipment, select a mask with a strong connection between the mask and strap. This is one place we see a lot of failures.

And most of all, make sure it fits your face before you pack your suitcase. :-)