Surf hipster bikini bottom in Ratti^® bahama print

I love the print so I’m keeping them since it’s the only bottom available in this print. It provides good coverage and is comfortable, BUT, why does everything have to be low riders??? So unflattering on most body types, causing muffin top and makes the legs look shorter. I am 5’7” 145#. I ordered the M and it fits ok, but I’m afraid it will sag when wet. If in between sizes, go with the smaller size.