Customer Rating: Summary: The absolute best to keep the mask from fogging up when diving! Comment: I have been diving for over 6 years now and i've been using Sea Drops from the start. Many people will tell you spit, or baby shampoo is just as good and cheaper, but you get what you pay for. While the others "MAY" work, Sea Drops do work all the time. i use 3 drops per lens and apply it when prepping the equipment for a dive. When you get to the water rinse the lenses and the mask will stay clear the whole dive. I would recommend the drops over the gel as the drops will last you longer and the gel is generally more expensive. I love this product and highly recommend it.