A waterproof cast, sometimes called a swim cast, is a fiberglass cast with a special waterproof cast liner or padding underneath. The outer layer is still a standard fiberglass cast, but the inner liner does not absorb water the way cotton padding does. This allows many patients, with their doctor’s approval, to shower with a cast or even swim with a cast while the bone heals.
In this guide, we explain how waterproof casts work, the different waterproof cast materials (including OrthoH2O, AquaCast, and Delta Dry), and how to care for a waterproof cast safely. While we offer all three systems, our primary recommendation for most families is OrthoH2O because of its simple one-piece design and patient comfort.
What Is a Waterproof Cast?
A traditional cast has two layers:
- A soft inner layer (usually cotton padding) next to the skin.
- A hard outer layer (usually fiberglass cast tape) that provides support and protection.
In a waterproof cast, the hard outer fiberglass layer stays the same, but the inner layer is changed to a synthetic waterproof liner. This liner does not absorb water like cotton. Instead, it allows water to flow through and drain out of the cast, so the skin can be rinsed and the cast can dry properly.
Waterproof Cast vs. Waterproof Cast Cover
Online, the term “waterproof cast” is often used for three very different things:
- Waterproof cast liners and padding – These are materials used inside a fiberglass cast. They are applied by a medical professional and become part of the cast itself. This is what OrthoTape sells in our waterproof cast collection.
- 3D lattice cast alternatives – Custom brace or cast alternatives with open, waterproof structures. These are a different technology from traditional fiberglass casts and may be available only through specific providers using specialized equipment.
- Waterproof cast covers – Plastic sleeves worn over a cast for showering or bathing. They do not make the cast itself waterproof; they simply try to keep water off a regular cast.
OrthoTape focuses on the first group: waterproof cast liners and waterproof cast padding that are used by clinics and hospitals to build a true waterproof fiberglass cast. We do not manufacture or sell disposable plastic cast covers. Newer 3D or lattice-style cast systems can look high-tech, but they are typically limited to select clinics and are often more complex and costly than simply using a waterproof liner under a standard fiberglass cast.
Types of Waterproof Cast Materials We Offer
OrthoTape carries three main waterproof casting systems. All of them work with fiberglass cast tape, but OrthoH2O is our preferred, streamlined option for most families and clinics.
One-piece waterproof cast stockinette that slips over the limb and is finished with fiberglass cast tape to make a waterproof arm or leg cast.
Two-piece system with waterproof stockinette and padding for clinics that prefer a wrap-and-pad technique.
Pillow-type waterproof cast padding in roll form, available in kits for short arm, long arm, and short leg casts.
1. OrthoH2O Waterproof Cast Stockinette
OrthoH2O (formerly OrthoNEAL) is a thick, fishnet-shaped cylindrical waterproof cast stockinette. It is hypoallergenic and made from advanced synthetic fibers designed to:
- Wick water away from the skin quickly.
- Drain water out of both ends of the cast.
- Reduce odor and moisture build-up compared to traditional padding.
OrthoH2O is a one-piece slip-on design that goes directly on the limb under fiberglass cast tape. When applied correctly, it creates a comfortable waterproof arm cast or waterproof leg cast that many patients can use for showering and swimming, with their provider’s approval.
You can shop OrthoH2O waterproof cast products here: OrthoH2O – Waterproof Cast.
2. AquaCast Waterproof Cast Padding
AquaCast is the original waterproof cast padding that uses a soft, pillow-type synthetic material in roll form. It was originally developed by the makers of Gore-Tex. AquaCast padding is wrapped around the limb and covered with fiberglass cast tape to create a waterproof cast.
AquaCast is available in dedicated kits (short arm, long arm, short leg) that include waterproof padding, saw-stop strip, and fiberglass casting tape. These kits are designed to be brought to your doctor’s office for application.
You can explore AquaCast waterproof cast kits here: AquaCast – Waterproof Cast.
3. Delta Dry Waterproof Cast Padding
Delta Dry is a two-piece waterproof cast system with synthetic stockinette and padding. The liner feels similar to nylon and allows water to pass through and drain while still providing soft support under the fiberglass cast.
Delta Dry is popular in clinics that want a familiar wrap-and-pad system but need the benefits of a waterproof cast.
You can view Delta Dry waterproof cast products here: Delta Dry – Waterproof Cast.
Can You Swim With a Waterproof Cast?
With a properly applied waterproof cast liner, many patients are allowed to swim in clean, treated pool water. Major pediatric orthopedic centers note that waterproof casts can be submerged in water but may not be appropriate for all fractures or all patients. Decisions about swimming should always be made by your treating provider.
Many hospitals recommend:
- Prefer swimming in clean, chlorinated pool water rather than lakes, rivers, or the ocean.
- Avoid sand and muddy water that can get trapped inside the cast.
- Rinse the cast well with clean water after swimming.
How to Dry a Waterproof Cast
After showering or swimming with a waterproof cast:
- Rinse the cast with clean water to flush out soap, chlorine, or debris.
- Hold the cast so water can drain from both ends.
- Pat the outside of the cast dry with a towel.
- Allow air to circulate around the cast until it feels dry.
- If recommended by your provider, you may use a blow dryer on a cool or low setting to help speed up drying. Do not use high heat.
The waterproof liner is designed to dry significantly faster than cotton padding, but the skin should still be monitored for irritation.
Is a Waterproof Cast Right for Every Patient?
Waterproof casts are not right for every injury or every patient. Some fractures, surgical incisions, or skin conditions may require a traditional cast and strict protection from water. In addition, waterproof cast liners can sometimes cause more skin irritation if not dried properly or if debris becomes trapped.
Always ask your orthopedic provider:
- Whether a waterproof cast is safe for your specific fracture or surgery.
- When you are allowed to shower or swim, and in what type of water.
- How to check your skin and what to do if you notice redness, rash, or odor.
How to Ask Your Doctor for a Waterproof Cast
Many clinics and hospitals do not stock waterproof cast liners or may have limited sizes and quantities. A simple option is to order a waterproof cast kit or liner from OrthoTape and bring it to your appointment.
Tips for talking with your provider:
- Call ahead and confirm they are comfortable applying a waterproof cast liner under fiberglass.
- Order the correct size kit (short arm, long arm, short leg, etc.) from our waterproof cast collection before your visit.
- Bring the unopened kit with you and show it to the casting technician or provider.
- Ask for written instructions about swimming, bathing, and how to dry the cast.
Waterproof Cast vs. 3D Lattice Cast Alternatives
In recent years, 3D-printed or lattice-style cast alternatives have been developed. These products can be waterproof, breathable, and removable, and are often highlighted in news articles as “casts of the future.” They are typically available only through specific clinics and may not be covered by all insurance plans.
By contrast, a waterproof fiberglass cast with a liner uses standard casting techniques and materials that many orthopedic clinics already understand. It is often a more accessible and cost-conscious option for families who want the ability to shower or swim while still using familiar fiberglass casting and keeping care close to home.
Where to Buy Waterproof Cast Materials
OrthoTape is an online medical supply company specializing in casting materials. We offer:
- Waterproof Cast Collection – OrthoH2O, AquaCast, Delta Dry
- OrthoH2O Waterproof Cast Stockinette
- AquaCast Waterproof Cast Kits
- Delta Dry Waterproof Cast Padding
These products are intended to be applied by a trained medical professional. If you have questions about whether a waterproof cast is appropriate for you or your child, always consult your orthopedic provider.
This information is provided for educational purposes only and does not replace professional medical advice, diagnosis, or treatment.