As you now know, most scuba masks are designed with a silicone skirt. Without going into too much detail on the benefits of silicone, buyers may be interested to know if this material tends to degrade and lose its shape over time. It really does not matter how many times you use it, a silicone skirt is going to remain durable and will not warp or degrade over time. Now, have common sense and take good care of your scuba mask and treat it with respect. If you do so, you should never have this issue present itself to you.