The second things I finished on vacation. Maybe an unpopulair opinion, but I think crochet bikini bottoms are more comfortable with swimming than regular bikini bottoms. (Marked NSFW because of wearing swimwear) :
Amazon.com: Women's Plus Size Swim Shorts - Black 2X : Clothing, Shoes & Jewelry
Ulla Popken Women's Plus Size Comfort Fit Cotton Panties Black 12/14 497459 10 at Amazon Women's Clothing store