Recording underwater requires specialized gear or protective housings because water destroys unprotected electronics and fundamentally changes how light and sound behave. Whether you’re capturing video on a reef, recording ambient ocean sounds, or filming a pool scene, the core challenges are the same: keeping your equipment dry, correcting for lost color, and managing sound in a medium where it travels nearly five times faster than in air.
How Water Changes Light and Sound
Water absorbs color wavelengths selectively. Red light disappears first, fading noticeably by about 15 feet (5 meters). By 80 feet, almost all warm tones are gone, leaving everything looking blue or green. This is the single biggest visual problem in underwater recording, and every solution below addresses it in some way.
Sound travels much faster through water than through air, and the distance it covers depends heavily on temperature and pressure. Standard microphones can’t pick up underwater sound effectively because of a physics problem called acoustic impedance mismatch. A regular microphone’s internal materials are so different in density from the surrounding water that sound waves bounce off rather than passing through. Dedicated underwater microphones, called hydrophones, solve this by using piezoelectric materials that flex under water pressure and convert that physical strain into an electrical signal.
Choosing a Camera or Housing
You have three main options for getting a camera underwater: a purpose-built waterproof camera, a waterproof housing for a camera you already own, or an action camera like a GoPro that’s water-resistant out of the box.
Action cameras are the simplest entry point. Most are rated to at least 10 meters (33 feet) without a case, covering snorkeling and shallow freediving. Check for an IPX8 or specific depth rating on the product page, since the exact limit varies by model. A 5 ATM rating means the device can handle pressures equivalent to 50 meters, which covers swimming, snorkeling, and shallow diving.
For interchangeable-lens cameras or higher-end compacts, you’ll need a housing. Polycarbonate housings are lightweight and affordable, typically rated to about 100 feet (30 meters), making them a solid choice for recreational divers and snorkelers. Aluminum housings cost significantly more but can handle depths beyond 300 feet, resist impacts better, and last longer. If you’re diving deeper than recreational limits or shooting professionally, aluminum is worth the investment.
Correcting Color Underwater
There are two ways to restore natural color: filters and artificial lights. Most people use one or the other, not both at once.
Red filters attach to your lens and compensate for the blue cast of clear saltwater. They work best between roughly 15 and 80 feet (5 to 25 meters). Shallower than 10 to 15 feet, there isn’t enough color loss to correct, and the filter just tints everything an unnatural red. Deeper than 80 feet, so little warm light remains that the filter can’t enhance what isn’t there. It will only darken your image. In green water (lakes, harbors, murky coastal areas), use a magenta filter instead of red.
Artificial video lights give you full control over color at any depth and are essential for close-up work in darker conditions. For macro subjects (small creatures, coral details), 2,500 to 3,800 lumens is sufficient. A general-purpose light in the 4,000 to 6,000 lumen range handles both macro and wider shots, though it may struggle to overpower strong ambient light in shallow, clear water. For professional wide-angle video, you want 8,000 to 15,000 lumens. Position lights slightly above and to the sides of your lens to reduce backscatter, the distracting snow-like effect caused by light reflecting off suspended particles.
Recording Sound Underwater
If you need actual underwater audio rather than just video, you’ll need a hydrophone. These sensors use piezoelectric elements that deform when hit by pressure waves in the water, generating a small electrical signal proportional to the sound’s intensity. You connect a hydrophone to a standard audio recorder (kept dry in a housing or left on a boat) via a waterproof cable.
Entry-level hydrophones suitable for nature recording or creative projects start around $30 to $50 for basic models, with professional units running several hundred dollars. The key spec to look for is sensitivity, measured in decibels relative to a reference level. A more sensitive hydrophone picks up quieter sounds like distant fish calls or shrimp clicks, while a less sensitive one suits louder environments without distorting.
For filmmakers who just need usable ambient sound, many action cameras capture muffled but recognizable audio through their built-in microphones. The results won’t be clean enough for a nature documentary, but they work for social media content or travel videos where you’ll add music or narration anyway.
Camera Settings That Work Underwater
Shoot in the highest resolution your camera supports, ideally 4K, because you’ll lose some detail to the reduced contrast and clarity of water. A higher frame rate (60 fps or above) helps with slow-motion editing, which is useful for marine life footage.
Set your white balance manually if your camera allows it. Auto white balance often overcorrects or shifts unpredictably as you change depth or angle. Point your camera at a white slate or white sand at your current depth, then lock the white balance to that reference. If you’re shooting raw or log video, you can skip the filter entirely and correct color in post-production, though this requires more editing skill.
Keep your ISO as low as possible to minimize noise, which is more visible underwater because low-contrast blue scenes amplify grain. Open your aperture wide in deeper or darker water, and let your video lights do the heavy lifting rather than cranking ISO.
Protecting Your Gear After Every Dive
Saltwater is corrosive enough to damage seals and buttons within hours if salt crystals are allowed to form. Rinse your housing in fresh water as soon as possible after leaving the ocean. If no fresh water is available at the beach, wrap the housing in a towel soaked in saltwater to keep it wet until you can rinse it properly. A gallon-size freezer bag filled with fresh water or a small cooler works as a portable rinse station.
Back at your room, give the housing a thorough soak in a sink. Press every button repeatedly while submerged to dislodge salt crystals that may have worked into the gaps. After soaking, dry the exterior completely before opening the housing to avoid dripping water onto your camera.
O-ring maintenance is what prevents leaks. Remove the O-rings carefully (some housings have two), wipe them clean with a cloth and fresh water, and inspect them by running the ring slowly between your fingers. Any nick, tear, or deformation means you need a replacement. Clean the groove the O-ring sits in, since salt and sand collect there. Then apply a thin coat of silicone O-ring grease with your fingertips. A light, even layer is all you need. Too much grease attracts debris and can actually compromise the seal.
Budget-Friendly Starter Setups
For snorkeling and pool recording, a GoPro or similar action camera with no additional housing gets you started for a few hundred dollars. Add a red filter (under $20) for tropical reef color correction and a small float handle to keep the camera from sinking.
For scuba diving with a phone, waterproof phone cases rated to 40 to 60 feet cost $30 to $80 and work surprisingly well in good light. Touch screens become unreliable underwater, so choose a case with physical buttons that trigger the shutter and record functions.
For serious underwater filmmaking, plan on a mirrorless camera, an aluminum housing matched to your specific camera model, a pair of video lights in the 4,000+ lumen range, and a tray-and-arm system to mount everything. This setup runs $2,000 to $5,000 or more depending on the camera body, but it produces broadcast-quality results at depths polycarbonate housings can’t reach.