How to Photograph Underwater Damage So It Holds Up Later
By Nadia Fournier, Marine surveyor and insurance adjuster. Reviewed by Dana Whitcombe, technical reviewer.
Underwater Inspection | Cathodic Protection & Anodes October 2018, San Pedro, inside the outer breakwater. The diver surfaced with a photo card and a tale about a damaged shaft. The water was the color of root beer, visibility maybe two feet, and his strobe was on full power. Every shot looked like a snowstorm—white flecks of backscatter drowning what was probably a clean crack in a propeller blade. I couldn't tell him if it was two inches or two feet long. I couldn't tell him if the blade touched the rudder or not. I asked him to go back down. That was the day I learned to write photo requirements into the survey order. I'm Nadia, a marine surveyor and insurance adjuster. I read underwater photos for a living, and I've seen more claims sink because of bad photos than because of bad damage. So if you're the diver holding the camera, or the owner paying someone to go look at the bottom, this is for you. Here's what I need from your underwater photos—and how to take them so they actually prove what happened.
Start with a picture of the boat itself
Before you even think about the damage, take a shot that shows you're on the right vessel. A survey slate with the boat's name, the date, and your company's name is ideal. Hold it against the hull, alongside the waterline or near the damage, and snap it. That photo might seem like a formality, but when I'm building a claim file, that's the page that ties the whole report to the policy. It also proves the diver was actually there on that day—not passing off an old photo from another boat. I once had a claimant try to submit a photo of a different vessel's bottom. The slate saved me.
Light it like you mean it
Underwater, light is the difference between a crack you can measure and a shadow that could be anything. The classic beginner error is to aim the light straight at the subject and shoot. That illuminates every particle of silt in the water—backscatter—and the damage disappears in white dots. For a flat surface like a hull, place the light at a low angle, maybe 30 degrees, and shine it across the surface. That raking light casts tiny shadows inside cracks and pocks, so they stand out as dark lines instead of blending in. Use a video light with a wide beam, or a strobe with a diffuser. And set your white balance underwater, or use a red filter. Without it, the photos come out blue-green and the damage details vanish. Practice on a barnacle before you need it.
Show scale, every time
A photo of a crack is just a fuzzy line until I know its size. I've had divers tell me 'the crack was about six inches' while holding a finger over it. I need a measured reference in the frame. A dive slate with centimeter marks works, but so does a 1/4-inch bolt of known length or a common coin. Just make sure the reference is flush with the damaged surface—not held up in the water in front of it, which distorts distance. Even better: take a photo with the reference at the start of the crack, and another at the end of the crack. That gives me the exact extent and is enough to calculate repair cost in most cases. If the damage is on a curved surface, also photograph a straight edge—like a ruler—along the damage so we can see it's not a trick of the camera.
Work from wide to tight, and overlap
Don't suddenly appear at a microscope level. I need to know where on the boat the damage is. Start with a wide shot that shows the whole area—say, the entire propeller blade—and then move in, each shot overlapping the previous by about 30 percent. This lets me follow the damage across the blade without getting lost. Then take close-ups of the edges, especially where a crack ends. A hairline crack will only be visible in a close-up, but the wide shot is what tells me how that crack relates to the blade tip. When possible, take three angles: down from above, from the side, and a 45-degree oblique. That gives me depth and shape. I can't turn your photos into a 3D scan, but I can tell if a dent is a dent or a gouge if you've covered the angles.
Take a narrated video for the messy truth
Stills are the skeleton, but video is the meat. After your stills, switch to video and pan slowly across the damage, narrating exactly what you're seeing: 'Crack starts at two o'clock on the blade, runs back toward the hub, depth looks shallow at the start but deepens to a quarter inch at the end.' Also name the location on the boat: 'This is the port propeller, facing aft, the crack is on the face of the blade.' That narration is crucial when a photo ends up in a contested claim. I can't ask you questions six months later; the video answers them. Record a 30-second clip, hold the camera steady, don't zoom—move slower than you think. Then upload it with the stills. A video doesn't need to be cinematic, it needs to be true.
Frequently Asked Questions
Do I need a special underwater camera for this? You need something with manual settings, especially for white balance and exposure. A GoPro with correct white balance can work, but a DSLR in a housing gives you the edge for macro work. The key is to know your gear, not just to own it. What should I do if the water visibility is really bad? Move closer to the damage, use a wide-angle lens, and rely on the video for context. If you can't see the full blade, take overlapping close-ups and label each one. Tell the client that visibility was poor—that honest note is better than a blurry photo that misrepresents the extent. How do I make sure the photos are accepted by the insurance company? Use a survey slate to identify the boat and date, include a scale reference, and shoot wide-to-tight. Then submit them organized and numbered, with a simple caption for each. That's what an adjuster needs, and it's all that separates a good claim file from a rejected one.