Hi Lexy. Whatever you end up using, make sure to apply it often, as IslandCruz recommended. Also use one that is waterproof, but reapply anyway.
One of our members, Penny3333, recommended Avon Skin so Soft SPF30 in another thread. I put it on my list of must-try items. IslandCruz, I've now added your choices, as well.
I'll usually use an SPF30, except for more sun-sensitive areas like my face, shoulders, backs of knees, when I will use an SPF50. I've noticed a difference.