For you moms who definitely want tummy coverage, one of the cutest and sexiest swim dresses I've seen this season is this number from Miraclesuit. It defines the narrowest part of your silhouette dramatically while providing boob coverage, a bit of cleavage and coverage for your butt and tummy. Thick straps provide extra support for the more buxom among you.
Though Urban Outfitters is notorious for featuring sickly skinny models, their trend toward the retro this season is actually a flattering style for the thicker-midriffed among us. This skirted retro one piece provides good all over coverage and in the right size (go for Large if you're an 8 or above) and on a normal body will incorporate and flatter a more curvy figure. It won't do, however, for anything larger than a C cup due to the stitching about the bust.
Though it is counter-intuitive, a high cut on the leg actually improves (slims) the look of your leg. Combined with ruching through the torso and its empire bust seam, this suit from Victoria's Secret would look great on size 8 and up shapes, and will incorporate and flatter a larger bust. If you're wondering, yes there is full coverage in the bum.
For the flatter chested among you, don't be afraid to go for an underwire suit to enhance your upper proportion. Here's an adorable print suit from Old Navy.
Another great trick for the thicker-middled is the halter top -- which, despite what you may think, works well for a larger bust (especially if the sides are higher). Old Navy always does well here.
A tankini can be a great boon to a troubling midsection, however, you need to look for one that is either loose fitting through the torso (has a bit of an A-line drape), or that has a longer torso, so you don't get stuck with a a reverse muffin top situation. Here's a nice A-line looks to cover your tummy.
And here's another.
Or check out this longer tankini top from Target which would look good with a boy short bottom or a traditional bikini bottom.
Here's a nice longer tankini from J Crew in a great selection of colors that you can mix and match with bottoms you already have.
The boy short is one of my favorite bottoms for enhancing while covering the rear and thigh and even the pooch. But beware of the boy short that has an elasticized leg hole – this will only squeeze your thigh and emphasize its width. Here is what a flattering boyshort should look like.