(Adult SM 60cm - 70cm Waist, Navy) - Reusable Swim Brief Nappy Adult Sizes

I have 49" waist,29"rise,194 lbs. My therapist wants me to get something for urinary incontinence in the pool. What size to I need, will this work?

Have a 48 inch waist what size will work for me...needed for swimming class what size do I need ?

Does this come in any other color besides navy?

Are these water tight? as in, no water gets in either?