The Dexcom G7 carries an IP68 water-resistance rating, which means the sensor itself can handle submersion in up to about 2.4 meters (roughly 8 feet) of water for as long as 24 hours. In practical terms, showers and casual swimming are fine. Hot tubs, though, introduce a different set of problems that the IP68 label does not fully address. The gap between what the electronics can survive and what the adhesive patch can tolerate is where most real-world frustrations begin.
What the IP68 Rating Actually Tells You
IP68 is a standardized rating for electronic devices, and each digit means something specific. The “6” indicates complete protection against dust ingress. The “8” indicates protection against prolonged immersion in water beyond one meter. For the Dexcom G7, Dexcom specifies this as submersion up to 2.4 meters for up to 24 hours. That rating applies to the sensor and transmitter hardware under controlled lab conditions with fresh water at room temperature.
What it does not cover is equally important. The rating does not account for the adhesive patch that holds the sensor to your skin. It does not account for hot water, chlorinated water, saltwater, soapy water, or water jets. And it says nothing about whether the sensor will still be stuck to your body after you get out. The electronics inside the sensor are well sealed. The challenge is everything around those electronics.
Showers Are the Easiest Scenario
A normal shower is the least risky water exposure for the G7. You are typically standing under a stream of warm water for five to fifteen minutes, which is well within the device’s tolerances. The sensor will continue reading your glucose levels without interruption, and the water itself will not damage the hardware.
The main thing to watch for is how you treat the adhesive patch. Direct, prolonged exposure to a high-pressure shower stream aimed right at the sensor can work the edges of the adhesive loose over time, especially if you are several days into a 10-day wear session. A simple habit change helps: angle the shower stream away from the sensor when possible, and pat the area dry rather than rubbing it with a towel afterward. Rubbing can peel up the adhesive edges faster than the water itself.
Soap and body wash deserve a quick mention. Soapy residue that works its way under the adhesive can reduce its grip. If you notice the patch lifting sooner than expected, consider washing around the sensor rather than directly over it, and rinsing the area with plain water before stepping out.
Swimming in Pools and Open Water
Pool swimming falls within the G7’s design parameters. The depth of a standard swimming pool is well under 2.4 meters in most recreational settings, and a typical swim session lasts well under 24 hours. The sensor hardware will survive without issue.
Chlorine is the variable that complicates things. Chlorinated pool water does not damage the sensor electronics, but it can degrade adhesive bond strength over repeated exposures. If you swim daily, you will likely notice the adhesive patch starting to peel at the edges sooner than it would for someone who only showers. A single swim session is unlikely to cause a problem. Three or four sessions across a 10-day sensor life starts to add up.
Saltwater swimming follows a similar pattern. The salt itself does not harm the sensor, but dried salt crystals under the adhesive edge can create tiny lift points that worsen with each subsequent exposure. Rinsing with fresh water after ocean swimming helps preserve the adhesive bond.
One practical note about Bluetooth connectivity: the G7 transmits glucose readings to your phone or receiver via Bluetooth, and Bluetooth signals do not travel well through water. While you are submerged, your phone will probably not receive real-time data. Once you surface or get out of the pool, the sensor catches up and fills in the gap. You will not lose your glucose data permanently; it just arrives with a short delay.
Hot Tubs and Saunas Are a Different Story
Hot tubs are where the “is it waterproof?” question gets more complicated, because heat and water together create problems that neither one creates alone. The IP68 rating was tested with water at a controlled temperature, not water at 38 to 40 degrees Celsius, which is a typical hot tub range.
Heat does two things that work against you. First, warm water softens adhesive faster than cool or room-temperature water. The medical-grade adhesive on the G7 is designed to hold firmly at skin temperature, roughly 32 to 35 degrees Celsius on the surface. Submerging it in water that is noticeably hotter than skin temperature accelerates the adhesive breakdown. Second, heat causes the skin underneath to sweat, even while submerged. That moisture layer between the adhesive and your skin weakens the bond from the inside out.
Dexcom does not explicitly prohibit hot tub use, but the combination of elevated water temperature, jets, and prolonged soaking is the scenario most likely to cause a sensor to fall off mid-session. If you regularly use a hot tub, plan for shorter soak times and consider applying an additional adhesive overpatch before getting in.
Saunas and steam rooms present a related but slightly different risk. The sensor is not submerged, but the extreme heat and humidity can loosen the adhesive in much the same way. Dry saunas in the 70 to 100 degree Celsius range push well beyond the temperatures the adhesive was designed for, and even brief sessions can compromise the patch’s grip for the remainder of its wear period.
The Adhesive Is the Real Weak Link
Almost every water-related complaint about the G7 traces back to adhesive failure, not electronics failure. The sensor and transmitter are robust against water intrusion. The thin adhesive patch that holds the unit to your upper arm is doing a much harder job: it has to stick to living, moving, sweating skin for up to 10 days through every shower, workout, and sleep cycle. Water exposure simply accelerates the wear on that bond.
Dexcom includes a built-in adhesive patch with each sensor, and for many users in dry or moderate climates who shower daily and do not swim, that patch holds for the full 10-day session. For anyone with an active lifestyle that involves regular water exposure, the built-in adhesive alone is often not enough.
Several strategies help:
- Skin preparation: Clean the application site with an alcohol wipe and let it dry completely before inserting the sensor. Any oil, lotion, or moisture on the skin at the time of application weakens the initial bond, and that deficit compounds over 10 days.
- Adhesive barrier wipes: Products like Skin Tac or similar medical adhesive wipes applied to the skin before sensor insertion create a tackier surface for the patch to grip. Many regular swimmers consider this step essential.
- Overpatches: Dexcom offers free adhesive overpatches that stick over the top of the sensor, essentially adding a second layer of hold. Third-party options from companies like GrifGrips and StayPut Medical also exist in various shapes and materials. For pool swimmers and hot tub users, an overpatch is often the difference between a sensor that lasts the full session and one that peels off on day six.
- Drying technique: After any water exposure, pat the area around the sensor dry. Pressing a dry cloth gently over the patch for a few seconds helps wick moisture from the edges. Never use a hair dryer on the sensor area; the concentrated heat can damage both the adhesive and the electronics.
Skin Irritation and Water Exposure
Water exposure can interact with the adhesive to increase the risk of skin irritation. A systematic review of trials and observational studies on continuous glucose monitoring found that cutaneous complications occurred at a rate of roughly one event per eight weeks of sensor wear, with the most common issues being redness, itching, and hardening of the skin at the application site. Only about 1.5 percent of those events were classified as severe.1Journal of Diabetes Science and Technology. Cutaneous Complications With Continuous or Flash Glucose Monitoring Use: Systematic Review of Trials and Observational Studies
Water by itself does not cause these reactions, but it creates conditions that make them more likely. When water seeps under a partially lifted adhesive edge and then dries, it can trap irritants against the skin. Chlorine residue, salt, and soap that get caught between the patch and your skin sit there for hours, which is a recipe for contact irritation. This is one more reason to rinse the sensor area with clean fresh water after pool or ocean swimming and to make sure the edges are dry and lying flat.
If you notice persistent redness or itching at the sensor site that worsens after water activities, it may be worth rotating your application site more aggressively between sensor sessions. Some people also find that applying a thin adhesive barrier wipe to the skin before insertion reduces direct contact between the adhesive chemicals and the skin, which can lower the irritation rate for those who are sensitive.
Does Water Affect Glucose Reading Accuracy?
Under normal conditions, brief water exposure does not interfere with the G7’s glucose readings. The sensor filament sits just under the skin in the interstitial fluid, and the electronic components that process the signal are sealed inside the waterproof housing. Showers, swims, and even hot tub sessions do not introduce water into the sensing pathway.
There is one edge case worth knowing about. If the adhesive has partially detached and the sensor filament shifts even slightly in the skin, readings can become erratic or drop out temporarily. This is not a water-specific problem per se, but water exposure is one of the most common causes of adhesive loosening, which then leads to sensor movement. If you notice unusual readings after a long swim or soak, check whether the patch edges are still firmly down. A sensor that is physically loose on your arm is going to give less reliable data regardless of whether water was involved.
Temperature changes can also cause brief, transient effects. Moving from a hot tub into cool air, or from a cold pool into warm sunlight, changes blood flow patterns in the skin. The G7 reads interstitial glucose, which lags behind blood glucose by a few minutes in normal conditions. Rapid temperature shifts can temporarily widen that lag. This is usually minor and resolves within 15 to 20 minutes as your skin temperature stabilizes.
What Happens If a Sensor Falls Off in the Water
Losing a sensor in a pool or ocean is not dangerous, but it is inconvenient and can be costly if you are between insurance refill cycles. The sensor is small, light, and will sink. In a pool, you can usually retrieve it from the bottom. In open water, it is gone.
Dexcom’s customer support will typically replace sensors that fail before the end of their 10-day life, including those that detach prematurely. If a sensor falls off during water activity, contact Dexcom with the sensor’s lot number and a description of what happened. Many users report successful replacements, though Dexcom evaluates these on a case-by-case basis and may ask follow-up questions about how the sensor was applied and whether overpatches were used.
One thing to keep in mind: a sensor that detaches cannot be reattached. The insertion mechanism is single-use, and the adhesive will not re-bond to skin once it has been peeled off. If it comes loose in the water, that sensor session is over. You will need to apply a new one.
Water Activities With Children Wearing the G7
Children with diabetes who wear the G7 face the same water-resistance realities as adults, with a few added considerations. Kids tend to be more active in the water, which means more mechanical stress on the adhesive from splashing, jumping, and rough play. They are also less likely to notice or care if an edge starts peeling. For children who swim regularly, overpatches and adhesive barrier wipes are close to mandatory rather than optional.
Sensor placement matters more for kids in aquatic settings. The G7 is approved for the back of the upper arm in adults and for either the upper arm or upper buttock area in children aged two and older. For swimming, the upper arm site tends to be more exposed to direct water flow and physical contact. Some parents find that the upper buttock placement, while slightly less convenient for daily wear, holds up better during pool time because it is more shielded from direct water jets and contact with pool walls or other swimmers.
Checking the patch edges before and after water activities, and pressing down any areas that have started to lift while the adhesive is still tacky enough to re-bond, can extend the life of a sensor session through a week of summer swim camp that would otherwise chew through multiple sensors.
Scuba Diving and Water Sports With Higher Pressure
The G7’s 2.4-meter depth rating puts a clear ceiling on underwater activities. Recreational scuba diving routinely goes to 12 to 18 meters, far beyond what the sensor is rated for. Dexcom does not certify the G7 for scuba diving, and exceeding the rated depth risks water intrusion into the electronics.
Snorkeling in shallow water is generally within the safe range, since you are typically at or near the surface. Surfing, kayaking, waterskiing, and other surface water sports fall within the depth tolerance, but they introduce mechanical forces that the adhesive was not designed for. A hard fall at speed on water can rip a sensor off. If you participate in these sports, a well-applied overpatch and possibly a neoprene armband over the sensor site offer extra insurance. Some people who waterski or wakeboard routinely wrap the sensor area with a self-adhesive cohesive bandage as a temporary shield, removing it after the session.
Freediving and competitive lap swimming at depth also push the boundaries. If you regularly dive below about two meters, you are exceeding the rated specification. Some users report that their sensors survive occasional deeper dives without issue, but this is anecdotal and outside Dexcom’s stated warranty coverage. A sensor that fails after being taken beyond its rated depth may not qualify for a free replacement.