Do the bikinis hold up in water and do they sag like most crochet bikinis?

Because the bikinis are made from 98.3% cotton and 1.7% elastic, they have great stretch like spandex, but the comfort and breathable quality of cotton. Spandex is synthetic and not good to wear in hot weather. Cotton is the best material to wear in summer weather. Because of the 1.7% elastic, the bikinis are 100 yards relaxed and 186 yards stretched. This is why the bikinis look smaller off the body, but fit you perfectly and hug your figure when worn. The elastic prevents the horrible sagging quality found in most other crochet bikinis on the market.

Does the attached jewelry get ruined in the water?

The jewelry attached to the bikinis is made of different metal including sterling silver. In different types of water it may tarnish. You can polish it with a silver cleaner or you can just leave it for an antique look.

Are the bikinis practical for diving and playing in the water?

Almost all the bikinis have tie sides. This allows you to adjust the tightness of the bikini. I wear all my designs and think that they hold up and stay on much better than most spandex bikinis. Some of the designs with jewelry sides are more delicate, but all my bikinis are made for swimming. Not just for laying on the pool side or on the beach. I can't give a guarentee, but they haven't fallen off me yet, and I wear them all the time and dive and fish in them.