Some underwater housings ship with a vacuum valve and a pump, or an electronic monitor that blinks green when the seal is holding. Others, including the DIVEVOLK SeaTouch 6 Pro, have no vacuum system at all. So which approach is right, and does a housing without one skip a safety step?
The short answer: no housing universally needs a vacuum system, and every housing needs a leak check. A vacuum check is a good way to catch assembly mistakes before you get in the water. Whether a particular housing should use one depends on its design and on what its manufacturer specifies instead. Below we cover what a vacuum check measures and where it stops, why opening size and seal design change the choice, and how the no-pump SeaTouch 6 Pro is checked.
What a Vacuum System Actually Measures
A housing vacuum system pumps some of the air out of the closed housing, which lowers the pressure inside relative to the air around it. A gauge or electronic sensor then watches whether that difference holds for a set period. If air leaks back in, the reading drifts and the system flags it.
A stable reading means the assembled housing did not lose vacuum faster than that system can detect during the test. That catches plenty of real problems: a door that is not fully seated, a seal that has rolled out of its groove, a loose port, a hair across a sealing face. The big advantage is that it checks the housing as assembled, with the camera or phone already inside, and gives you an objective result on top of what your eyes can see.
Each system sets its own target reading, wait time and pass rule, and those details do not transfer between brands. Some use a hand pump and a gauge, some an indicator that changes color, and some an app that runs a timed analysis. All of them are sensitive to temperature, because gas pressure changes with temperature. Loading a hot phone, or carrying the housing from an air-conditioned room into the sun, can shift a reading without any leak. Run the test the way your manual says, in the conditions it describes.
What a Vacuum Check Does Not Tell You
At the surface a pump can only remove part of the one atmosphere of air around the housing, while the water outside adds roughly an atmosphere for every 10 meters, as NOAA's National Ocean Service explains. Ikelite's vacuum pump instructions spell out the consequence: a surface vacuum simulates depth only to about 10 meters, and a fine hair across an O-ring can cause a leak that only appears deeper. A vacuum check is a low-pressure screen for assembly errors. It does not test the housing at full depth.
The depth rating is a separate figure the manufacturer publishes for the product, and a passing vacuum check does not extend it. For the SeaTouch 6 Pro that rating is 60 meters, and we explain why the gap between that number and the depth you actually dive matters in why depth margin matters on the SeaTouch 6 Pro.
A vacuum check also does not inspect the seal for you. It cannot see a nick that has not opened yet, it does not know the housing took a knock on the ladder after you tested it, and it says nothing about the housing once you open and reclose it. A moisture alarm, where fitted, is different again: it reports water that has already reached the sensor.
Why Opening Size and Seal Design Change the Question
Camera housings for full-size bodies often open along the whole back or front. That is a long seal line, frequently an O-ring that the user removes, cleans, lubricates and reseats. The longer the seal and the more steps involved in seating it, the more places a hair, a grain of sand or a twisted ring can hide. A vacuum check suits that design well, because it gives an objective check on a large closure that is hard to inspect perfectly by eye.
A phone housing with a small opening has far less seal line to keep clean, so there is less to inspect, though a short seal with one hair across it still leaks. Seal count works the same way: several layers add defense, but layers that share a closing surface can be defeated by the same contamination. The Parker O-Ring Handbook treats a seal as part of a designed groove with set compression, finish and tolerances, which is why a seal is only as good as the surface it closes on.
Opening size and seal design are reasons a manufacturer might choose one leak-check method over another. They decide how you check, and the check itself stays.
Worked Example: SeaTouch 6 Pro Without a Vacuum Pump
DIVEVOLK states that the SeaTouch 6 Pro needs no vacuum pump. The phone seals in seconds and the housing is ready to enter the water without a pump or setup routine. The design reasons DIVEVOLK gives are a minimal seal-cover design, three layers of precision seals and a buttonless body, which means no mechanical control shafts passing through the wall. We look at each of those in inside SeaTouch 6 Pro leak prevention, and DIVEVOLK's wider reasoning for leaving out vacuum pumps and alarms is in its housing design philosophy.
DIVEVOLK's housing seal care guide also says its housings are not designed to be vacuum-pump tested. Do not try to add one: drilling a port or fitting an aftermarket valve changes the pressure boundary and is not something any manufacturer's rating covers unless it approves that exact modification.
The pump's job goes to your eyes and hands, and with no gauge behind them the inspection carries more weight:
- Load in a dry, clean spot. Away from spray, blowing sand, wet towels and sunscreen-covered hands.
- Inspect the sealing surfaces before closing. Look in good light and run a clean fingertip along the seal and its mating face. Anything you can feel, water can get past.
- Check the membrane and glass. No cuts or grit pressed into the touch membrane, no chips in the lens glass.
- Close it as the manual shows, then look along the seal line for anything pinched or lifted.
- Test function. Tap and swipe across the whole screen and take a test frame. Remember that the phone's own buttons cannot be pressed inside the housing; every control goes through the touchscreen.
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Water-test empty when it counts. When the housing is new, after a seal change, or after anything unusual, close it without the phone and submerge it in fresh water, watching for a stream of bubbles. DIVEVOLK's seal care guide describes this test for the SeaTouch 4 Max family; confirm the procedure for the 6 Pro in its manual. This is an at-surface check; like a vacuum test it cannot reproduce depth pressure, so anything unclear goes to support.
The full routine is in the six essential housing checks, and the phone-side setup is in the pre-dive phone and housing setup guide. The trade-off is plain: a no-pump housing is faster to close and has no valve, pump or battery to manage, while a vacuum housing adds an objective reading to your inspection.
Leak Checks Do Not End at the First Closure
A check is only valid for the assembly you checked. Once you open the housing to charge the phone or move files, the seal you inspected that morning is gone and you are building a new one. On a boat that is the step people rush. Our guide to keeping your phone in its SeaTouch 6 Pro between dives covers when to reopen and how to reseal on a wet deck.
At the end of the day, rinse the housing closed in fresh water, dry the outside and your hands, then open it. Our post-dive housing cleaning steps keep salt off the sealing surfaces so the next morning's inspection starts clean.
In the water, watch for droplets, fog that keeps building, or a touchscreen that starts behaving oddly. If you suspect water is getting in, the dive plan comes first: keep your buoyancy, gas and buddy contact, and ascend normally. A phone is never worth a rapid ascent. The same order applies before the dive, where a predive safety check on your own gear comes ahead of any camera check.
Does Your Housing Need a Vacuum System?
Ask these questions about the specific housing rather than about housings in general:
- Does the current manual call for a vacuum check, offer it as an approved accessory, or say the housing is not designed for one?
- If there is no vacuum system, which visual, function and water checks does the manufacturer specify instead?
- Can you actually see and clean the whole seal before closing?
- What is the published depth rating, and is it comfortably deeper than the dives you plan?
- What does the manufacturer tell you to do after a failed check, an impact or a damaged seal?
If the answers point to a vacuum system, use the one the manufacturer approves, exactly as written. If they point to a no-pump routine like the SeaTouch 6 Pro's, run it every time with the same care. If anything in your manual is unclear, ask DIVEVOLK technical support before you put a phone inside.
