Fantasea FRX100 VA R Housing for Sony RX100 III / IV / V / VA (*)

Before every dive, open the housing somewhere clean and dry, inspect and wipe the main o-ring and its groove, and close it with nothing trapped in the seal, because a single hair or grain of sand is enough to flood it. Confirm every latch is fully closed and that any vacuum or leak alarm reads correctly. Where you can, soak the sealed housing in a rinse tank or hang at the surface before descending, so a leak shows up before depth.

Remove the main o-ring regularly with a plastic tool rather than anything metal, which can nick the groove, and clean both the o-ring and the groove with a lint-free cloth. Apply a thin film of the silicone grease the manufacturer specifies, since grease helps the o-ring seat and slide rather than sealing by itself, and a thick coat only collects grit. Replace o-rings on the schedule in the manual, or sooner if they look flattened, cut, or dry.

A moisture alarm is a sensor inside the housing that beeps or flashes when it detects water, giving you a chance to abort the dive before the camera is ruined. Desiccant packs absorb humidity in the air sealed inside the housing, which prevents the port fogging as you descend into cooler water. Neither replaces a proper seal check, since they provide early warning and fog control rather than leak prevention.

Only as deep as its rated depth, which the manufacturer sets and publishes in the specifications, and it should never be exceeded even briefly. Depth ratings assume a housing in good condition with intact seals, so worn o-rings or a damaged port reduce the real margin. If your diving might take you deeper, choose a housing rated comfortably beyond your planned maximum depth.

Only if the housing is specifically rated for the depth you plan to dive, because many phone cases are splash- or snorkel-rated rather than scuba-rated. Touchscreens generally do not respond underwater, so a diving phone housing needs mechanical buttons or another control method. A phone's own water-resistance rating is not a substitute for a housing, and any housing still needs seal checks and o-ring care.

Soak the closed, sealed housing in fresh water and work every button and dial while it is submerged so salt does not dry inside the control shafts. Let it dry completely, especially around latches and seams, before you open it, since opening a wet housing drips water straight onto the camera. Avoid opening a housing on a wet, moving boat deck whenever you have the option to wait.

Get the housing out of the water and open it somewhere dry, then immediately remove the camera's battery and memory card, because leaving a battery in a wet camera does more damage than the water itself. Do not power the camera on to check whether it still works. Dry everything gently away from direct heat, get salt-water-exposed equipment to a repair technician promptly, and inspect the housing to find which seal failed before you dive it again.

The FRX100 VA R Housing is built for the Sony Cyber-shot RX100 III, RX100 IV, RX100 V and RX100 VA digital cameras. It is not published as compatible with other Sony RX100 generations. If you are unsure which RX100 model you own, check the model number printed on the camera body or its manual before ordering.

No, the M16A Vacuum Valve is not included and is sold separately. The housing ships with an M16 port designed for that valve plus a built-in rechargeable moisture detector and alarm, so you can monitor water tightness during a dive even before adding the vacuum valve.