I have always hated swimming caps - the tightness of them and then always having to pull down as they slide up.
Someone in my water aerobics class was wearing a diving cap with a strap under the chin. I thought, to bad they don''t make swimming caps like that or, maybe they do.
I looked on Swim Outlet and they had several swimming caps with chin straps. I choose this one and I am very happy with it. During winter months our pool is covered by a bubble which drops condensation onto our heads. Also, it is colder getting out of the water with wet hair during the colder seasons.
I am thinking I will also wear this in summer to prevent my hair from getting so much water splashed on it. The chlorine tends to remove my hair coloring.