The Dexcom G7 is waterproof when submerged in up to 2.4 meters (about 8 feet) of water. You can shower, bathe, and swim while wearing it. However, there’s an important catch: Bluetooth signals don’t transmit underwater, so your sensor readings won’t reach your phone or receiver while you’re submerged.
What “Waterproof” Actually Means Here
Dexcom rates the G7 as waterproof at depths up to 2.4 meters. That covers lap swimming, wading at the beach, showering, and bathing. It does not mean you can take it scuba diving or wear it in a high-pressure water environment. As long as you stay within that depth limit, the sensor itself will continue working normally.
This is a slight upgrade in language from the previous Dexcom G6, which was described as “water-resistant” at the same 2.4-meter depth. The G7 carries the stronger “waterproof” label, though the practical depth limit hasn’t changed.
Bluetooth Stops Working Underwater
Water blocks Bluetooth signals. While you’re submerged, the G7 sensor can’t send glucose data to your phone, smartwatch, or receiver. This means you’ll have a gap in your real-time readings during a swim or long bath. The sensor continues measuring glucose the entire time, but the data only syncs once you’re out of the water and back within Bluetooth range (about 20 feet with no obstructions).
For most swimmers, this creates a gap of 30 minutes to an hour. If you’re concerned about lows during exercise, checking your glucose before getting in the water is a practical workaround.
Keeping the Sensor Attached in Water
The G7’s built-in adhesive patch holds up reasonably well during brief water exposure like showers. Longer or repeated submersion, especially in pools or saltwater, can loosen the edges over time. If the adhesive starts peeling, the sensor may shift or fall off before its 10-day session ends.
Dexcom recommends using additional adhesive patches or tape over the sensor to reinforce it. A few approaches that work well:
- Overpatches: Dexcom provides free overpatches through their website. These cover the entire sensor and add a second layer of hold.
- Third-party adhesive products: Brands like Hypafix, GrifGrips, and Simpatch are specifically noted for maintaining excellent adhesion even when wet.
- Picture frame technique: Cut adhesive tape into strips and apply them around the edges of the sensor patch, framing it without covering the transmitter window.
If you use a separate adhesive patch, cut a hole over the transmitter so it isn’t obstructed. Applying any overpatch to clean, dry skin before you get in the water gives you the best hold.
After You Get Out of the Water
Once you’re out and dry, Bluetooth reconnects automatically and your readings resume. Gently pat the sensor area dry rather than rubbing it, which can peel up the adhesive edges. Avoid using a hair dryer directly on the sensor. If you’ve been in chlorinated or saltwater, a quick rinse with fresh water around the sensor site (not pulling at the patch) helps prevent skin irritation over the remaining days of wear.
Hot Tubs and Saunas
Water resistance and heat tolerance are two different things. The G7 sensor has an operating temperature range, and prolonged exposure to hot tubs or saunas can push the sensor beyond its limits. High temperatures may affect glucose readings or the adhesive bond. Brief exposure is less of a concern than sitting in a hot tub for an extended session. If readings seem off after heat exposure, give the sensor a few minutes at normal temperature to stabilize before acting on the numbers.