Hi brittany- So the best waterproof mascara I've tried is Maybelline Stiletto lash waterproof. I know it's not Sephora, but it's awesome for lengthening(looks like you have false lashes!) and it stayed on when I was in the pool and underwater for an hour and a half with very minimal smudging. Another good one is the Maybelline falsies waterproof. It's not as awesomly lengthening as the other but still waterproof. Only complaint I have about these two is that it's pretty hard to get them off with remover. I usually do a couple rounds of remover after the pool and wash my face twice in the shower. Sometimes I even use more remover after the shower! I don't recommend them for daily wear since they are sooo hard to get off. Hope this helps you!!
Answered[ Edited ]
I just bought the stretch mascara in the giorgio armani eyes to kill . So I have to go back now and give my new favorite mascara kudos. They'll never be another one that I'll choose over this. Rock Star of lengthening mascara.
Fresh face I wanted to add that there is another mascara that you might want to try and that is the dior extase.