The Dexcom G6 sensor and transmitter are water-resistant, not waterproof. You can shower and swim with the sensor and transmitter on your body, but the handheld receiver is not water-resistant at all and should never be submerged or exposed to moisture. The distinction matters because different components of the system handle water very differently.
Sensor and Transmitter vs. Receiver
The sensor and transmitter that sit on your skin are designed to withstand brief water exposure from activities like showering, bathing, and swimming. You don’t need to remove them or cover them with plastic before getting in the water. However, Dexcom’s own safety documentation makes a clear distinction for the receiver: “Do not submerge your receiver in water and do not get dirt or water in the USB port.” Water damage to the receiver is not covered, so leave it poolside or in your bag.
If you use a smartphone as your display device instead of the receiver, the same common-sense rule applies. Keep your phone dry unless it has its own water resistance rating.
Bluetooth Signal Loss in Water
The biggest practical issue with water isn’t damage to the sensor. It’s losing your glucose readings. Bluetooth signals travel poorly through water, so the wireless range between your transmitter and your display device drops significantly when you’re submerged. Under normal dry conditions, the transmitter communicates with your receiver or phone up to about 6 meters (roughly 20 feet) away. In a pool, bathtub, or even on a waterbed, that range shrinks dramatically.
This means you’ll likely have gaps in your glucose data while swimming. The sensor continues measuring glucose under your skin, but the readings may not reach your phone or receiver until you get out of the water and the two devices reconnect. For most people, short gaps during a swim aren’t a problem since the system backfills data once the connection is restored. If you want to minimize signal loss, keep your display device as close to the pool edge as possible.
Keeping the Sensor Attached in Water
Water resistance of the sensor itself is only useful if the adhesive patch stays stuck to your skin. The built-in adhesive can loosen with repeated water exposure, especially during long swims or in chlorinated pools. Once the edges start peeling, the sensor becomes more likely to catch on clothing or fall off entirely, potentially ending your session early.
Dexcom recommends several overlay patches that maintain strong adhesion even when wet:
- Hypafix: a medical-grade adhesive tape you cut to size
- GrifGrips: pre-cut adhesive patches designed for CGM sensors
- Simpatch: another pre-cut option with a hole for the transmitter
Applying one of these over the sensor before you swim gives you the best chance of keeping everything secure for the full 10-day session. Some people apply an overpatch from day one as a preventive measure, while others wait until the original adhesive starts showing signs of lifting. Either approach works. If you’re a daily swimmer, starting with an overpatch from the beginning will save you frustration.
Tips for Swimming and Water Activities
Before getting in the water, make sure the edges of your sensor patch are firmly pressed down. Loose edges act like scoops that catch water and accelerate peeling. Pat the sensor area dry with a towel after swimming rather than rubbing, which can pull at the adhesive. Avoid directing a strong shower stream right at the sensor for the same reason.
Chlorine, salt water, and hot tub chemicals can all degrade adhesive faster than fresh water. If you spend a lot of time in pools or the ocean, you may find that your sensor adhesive loosens a day or two earlier than it would otherwise. An overpatch solves this for most people. Some users also apply a thin layer of skin barrier wipe (like Skin Tac) before inserting the sensor to give the adhesive extra staying power from the start.
One last thing worth knowing: prolonged soaking in very hot water, like a hot tub or long bath, can occasionally affect sensor readings temporarily. This isn’t a water damage issue but rather a result of changes in skin blood flow from the heat. Readings typically normalize within 15 to 30 minutes after you get out.