tomboyx | Premium Underwear for All Day Comfort. Fit for You.

Swim 7" Heritage Board Shorts Heavy Weight

Swim 7" Heritage Board Shorts Heavy Weight - Main image
$53.28 $74 In stock

Category: swimwear

Reveal an aquatic surprise with our water-activated fabric. When dry, black keeps its secrets hidden. But splash some water on it, and watch as gray jellies emerge.

How It Works

Our innovative color-changing technology responds to water contact. The moment moisture hits the fabric, the previously invisible jellyfish print transforms from black to gray. Once dry, the fabric returns to its sleek, all-black appearance—ready to surprise again and again.

Lightweight & relaxed shorts with an anti-chafe inseam that takes you from beach to trail to smoothie stand.

Sustainability note: We recycle 7-14 water bottles to make each 7" board short

  • 7" inseam
  • Lace-up front closure with zipper and hook
  • Back velcro-closed patch pocket
  • UPF 50
  • Chlorine & saltwater resistant
  • Anti-cling, anti-static, anti-chafe
  • Shell: 90% recycled polyester; 10% spandex
  • Fitted brief lining: 80% recycled polyester; 20% spandex 
  • OEKO-TEX Certified
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Standard Shipping: Handling (business days) 0–1; Transit (business days) 7–15.

Express Shipping: Handling (business days) 0–1; Transit (business days) 7–15.

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Delivery costs

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Standard Shipping · United States: $0.00

Express Shipping · United States: $3.99

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Returning an item

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United States · Return window (days after delivery): 30. Return method: By mail. Return postage: Seller pays.

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Customer Reviews (5.0 / 5 · 5 reviews)

Lily ★★★★★

The fabric is seriously heavy-duty—you can tell it’s built to last. I wore them all day at the beach and they dried surprisingly fast, plus the hidden jellies appearing when I dove in was such a fun surprise for my kids.

Benjamin S. ★★★★★

The jellies only show up when wet, which made the reveal at the beach genuinely fun—my kids kept splashing me to see them again. The heavy weight fabric feels substantial and held up well after a full day in the ocean.

Ruby ★★★★★

The water-activated reveal is the coolest thing—I dunked the leg in the pool and gray jellies appeared instantly, then faded back to black once dry. The heavy weight fabric feels substantial and hides any wet-suit cling, which is exactly what I wanted for beach days.