Will A Swimsuit Expand In Water?

Swimming in the sea off a public beach is tremendous fun, as we all know, but until recently, I could not rid my daughter of the fear that she would lose her swimsuit. It wasn’t the waves that bothered her but the possibility that the swimsuit might expand and return to the beach without her.

A swimsuit will expand slightly in water because of the materials’ elasticity. Constant wave action or sea sand entering the suit can cause stretching over time. Correct garment care is important for delaying the degradation of the fibers, and buying a swimsuit one size up should be avoided.

If you’ve spent some time on a beach with decent waves, you’ve certainly seen your fair share of bikini tops coming adrift – great fun for teenage boys! – or of bottoms taking on sand and dropping an inch or two. What about swimsuits expanding in the water, either in a pool or the sea?

Will Your Swimsuit Expand In Water?

Lycra is a fabric most often used in swimsuits and will stretch temporarily in water but will revert to its original shape and size when dried. Over time, however, the suit will sag somewhat. One swimsuit designer suggests that you do not ‘size up’ if you plan to spend much time in the water, particularly if there are waves present.

Other materials often used in swimwear are nylon, polyester, and spandex, all of which have very similar stretching properties and will last years with a little care.

Rather size down or size exactly to your body shape if you will spend time in the water, although sizing up is perfectly acceptable if you plan to spend most of the time sunbathing or relaxing in some other way. There won’t be much visual difference when you size correctly, but you will be able to feel it.

There are also swimsuits with bows or ties that you can use in conjunction with sizing up. Certainly, you shouldn’t compromise on support or shape, and with lacing and rear ties available for women, there are plenty of choices.

Sizing up will give the water and sea sand easier access to your swimsuit, so from the practical point of view, it increases your chances of a ‘wardrobe malfunction,’ the dreaded ‘sagging butt syndrome,’ or loss of the entire garment.

Paddle-boarding, surfing, or even swimming lengths call for sizing down. In this way, the suit will expand only slightly but won’t compromise you other than in the most extreme circumstances.

Can The Swimsuit Material Increase/Decrease Expansion In Water?

Different materials in your swimsuit have two things in common; they retain shape and repel water. However, small differences do exist:

  1. Nylon – Often used for female swimmers due to its figure-hugging properties, nylon is usually combined with a low percentage of spandex or lycra for added elasticity. It dries quickly and is soft to the touch.
  2. Polyester – Smooth to the touch, polyester is used by many competitive swimmers as there is very little drag through the water. To the beachgoer, this translates to fewer foreign particles entering your suit and less sag (expansion).

What Causes Swimsuit Expansion In Water?

Leaving sand in your swimsuit for ages because you’re too shy to tip it out before you leave the sea will cause instant bulging and stretch the suit over time. A quick remedy is to kneel in the water and quickly sloosh out the suit before you return to the beach.

Tips On Avoiding Unplanned Swimsuit Expansion

  • You’re more likely to stretch the garment by wringing it out after rinsing or washing it, so avoid this like the plague.
  • Sun and chlorine are other culprits, so dry your suit in the shade where possible and rinse the salt or chlorine from your swimsuit at the end of the day. The ultraviolet rays from the sun feel great on your skin but damage the elastic in your swimsuit over time.
  • A good rinse in cool or cold water as soon as possible may seem unnecessary, but your suit will almost certainly contain some combination of sunblock cream, chlorine, sweat, sand, dirt, and salt. This removes tiny particles before they can damage the fabric.
  • Avoid washing machines on wash day. Even on the most gentle cycle, a machine may damage the suit’s integrity over time.
  • Wash by hand with a mild soap, using gentle movements, and as suggested earlier, never wring the swimsuit out.
  • I suggest a gentle squeeze to remove the bulk of the rinse water, followed by drying the suit in the shade on a towel.

If you are a lover of hot springs, don’t believe you are immune from swimsuit expansion, as the sulfur and other minerals in hot pools will also need to be cleaned from your swimsuit in the same way described above.

If you are particularly concerned about your swimsuit expanding, consider looking for the label Lycra XtraLife in your next swimsuit. The technology employed will extend the life of the swimsuit by seven to ten times, but naturally is more costly than the standard lycra.

Tips On Choosing A Swimsuit

  • Temporarily stretch the swimsuit by hand before you even try it on. It should stretch under tension but return to its original shape and size when released. If not, it will do the same in the water, so move on to the next swimsuit.
  • Do a little jerky dance if the changing room at the store allows. If the swimsuit pulls, digs into your body, or starts to annoy you, it’s a sure sign of what will happen if you wear it for several hours in the pool or at the beach.
  • If the store permits you to take the garment home, lounge around for a few minutes in typical pool-side positions. You’ll soon know if you’re on the right track.

Some Swimsuit Brands You Can Trust

There are several excellent swimsuit brands on the market, and these ten are simply a short-list to help you with your choices:

  1. Speedo
  2. Nike Swim
  3. MP Michael Phelps
  4. Finis
  5. Orca
  6. Adidas
  7. TYR
  8. Arena
  9. Mad Wave
  10. Aqua Sphere
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The amount of expansion a swimsuit suffers in water is negligible. Buy the style and size correctly for your own body shape, rinse and clean it carefully, and you should have no issues for several years.