QuestionBest action camera for scuba diving? And how do I stop my footage looking blue-green?

I'm Open Water certified and heading on my first proper dive trip, to the Maldives, in about two months. Max depth should be around 18m.

I want to film it, but last year I tried snorkelling with my phone in a waterproof pouch and every clip came out as blue-green soup. A turtle swam right past me and it's just a silhouette in the file, and the coral looks grey.

Budget is roughly $450 for the camera. My questions:

1. Which camera should I get? I'd love to avoid a housing, because I've read they fog up.
2. Someone mentioned a "red filter". Do I need one?
3. Are there settings I should change, or is it all down to the camera?
4. Do I need lights, or is that just for pros?

Cheers.

cant help on the camera but get your buoyancy sorted before you worry about footage. every wobbly dive video ive seen was a buoyancy problem not a camera problem

Bueno, good news first, all of this is fixable and almost none of it is the camera's fault. Water takes the colours away in order, red is basically gone by 5m, then orange and yellow, and by 15m you are recording mostly blue and green. Auto white balance cannot bring back a colour that never arrived to the sensor, so the recipe is the right camera, manual white balance, a filter, capped ISO, and maybe two minutes of colour work per clip. Prices are from 28 Sept.

Camera first, because depth rating is where they differ most. Without housing: DJI Osmo Action 6, Osmo Action 5 Pro and Insta360 X6 are 20m, the Insta360 X5 is 15m, the Ace Pro 2 is 12m, the GoPro HERO13 Black 10m and the GoPro MAX2 only 5m. The Insta360 Luna Ultra has no water, dust or splash resistance at all, keep it away from the sea completely.

For 18m and $450 I would look at the DJI Osmo Action 5 Pro ($319 at B&H, 20m bare, 60m in the case) or the Osmo Action 6 ($436 at B&H, DJI dont officially sell it in the US). Of the waterproof flat cameras on that list the Action 6 has the best low light hardware, 1/1.1" sensor and a variable f/2 to f/4 aperture. Below about 10m I would set it to f/2 yourself instead of trusting auto. If you can stretch to $699.99 the Insta360 X6 is also 20m bare (60m cased), has PureVideo for low light, and it is 360, so you choose where the camera was pointing after the dive, which is very handy because the turtle will not wait for you to pan. The Ace Pro 2 ($369.99) is a lovely snorkelling, freediving and macro camera with the flip screen and 13.5 stops of dynamic range, but at 12m it is not a scuba camera without a case.

One warning. 18m on a 20m rating is not much margin. The rating is a static pressure test, real diving adds salt, temperature shock and a door seal opened hundreds of times, so treat the number as the outer edge. For the deeper dives I would use the maker's own case (Action 5 Pro and X6 both publish 60m cased). And always rinse it in fresh water the same day and check the gasket for sand before every dive, one grain on the seal is the whole failure.

About housings fogging, it is avoidable. Seal it in the driest, coolest air you can find, not on a humid boat deck, put two or three desiccant strips along the sides, and keep the camera cool before you close it. There is no fix once you are in the water. Get the manufacturer's case with a glass port, not acrylic, and check it takes a filter.

White balance is the biggest single fix. Set it manually, roughly:

0-5m: 4500-5000K 5-15m: 5500-6500K 15m and deeper: 6500-8000K

Even better, at your working depth fill the frame with something neutral (white sand, a slate, the back of a white fin) and set a custom white balance from it, and redo it if you change depth more than 5m or so. Do this even if you shoot flat, a flat profile does not recover colours that never reached the sensor.

Filters, yes, a red one for clear blue tropical water like the Maldives. Most makers say it works from about 3 to 15m, maybe 20m at a push. Magenta is for green water (kelp, lakes, coast). Shallower than about 3m skip it, manual white balance is enough and the filter looks fake. Remember it costs you one or two stops of light and it is a fixed correction, so the filter that saves a shot at 12m makes a shallow shot look like a sunset. A flip mount that swings out of the way is better than screw on. And check a filter actually exists for your camera and fits your case before you buy.

Settings. Cap the ISO yourself, auto will happily go to ISO 6400 on a wreck and that footage is useless. In clear water shallower than 10m I keep ISO 100-400, shutter 1/60 at 30fps or 1/120 at 60fps, EV 0. Murky or overcast, ISO 400-800, 1/60 at 30fps, EV +0.5. Deep reef below 15m, ISO 800 max, 1/60 at 30fps, EV +1.0 and bring a light. Shooting up towards the surface, ISO 100-200, 1/120, EV -1 to -2. Shutter at double the frame rate, and 60fps for anything fast so you can slow it down.

Stabilisation, leave it on for wide reef shots. For very close macro (inside 30cm or so) some people turn it off and brace with both hands because the stabiliser can warp the edges, worth trying both. Horizon lock I turn off underwater, I found it tilts things for no reason, the exception is a 360 camera where you level it in the edit. And your buoyancy, like hannah says, no setting fixes that. Get neutral, stop finning, then press record, two seconds of stillness before and after the shot is worth more than anything else.

Lights. Filter plus manual white balance takes you far, but below about 15m a light stops being optional for good colour and 18m is in that zone. Get a video light, not a dive light, a dive light is a narrow hot spot and a video light is a wide even flood. For fill on a shallow reef 500-1,000 lumens at 90-120°, for deep reef or wrecks 2,000-4,000 lumens at around 120° and about 5000K. Put it on an arm 15-20cm off the tray, not on the camera, or you get backscatter, and aim it slightly outwards.

Colour correction after, about two minutes a clip. First white balance with the picker on something neutral (sand, slate, grey rock), and if there is nothing neutral start around 8000K and push the tint towards magenta. Then contrast, shadows down a bit, highlights up, gentle S-curve, and stop before you want to. Then hue vs hue, blues a little to cyan and greens a little to yellow. DaVinci Resolve free does all three. CapCut also, but only up to 4K on most setups. Gyroflow is free and stabilises afterwards from the gyro data, useful if you shot macro with stabilisation off. If you go for an Insta360 360 camera like the X5, the 8K export needs Insta360 Studio on a computer.

Audio, don't bother, the mics cannot record anything usable underwater. Mute it, record narration after and put some topside sound underneath (waves, the boat).

Tell me which camera you pick and I can suggest settings for that one.

Good write-up. One thing I'd add on the grading side: resist the urge to crank saturation once the white balance is fixed. Underwater footage goes radioactive very quickly, and coral that looks neon reads as fake to anyone who dives. Fix the balance, set contrast, then pull saturation back a notch from where you think it should be.

Wow, thank you, this is far more than I expected. So the Action 5 Pro, a red filter on a flip mount and maybe a cheap video light later sounds like the plan within budget. @Marta_G would you use the case for every dive at 18m or only the deeper ones? Worried about the fogging still.

If most of your dives are near 18m I would just use the case for all of them, it is one less thing to think about and the margin is too small for my taste. Do the desiccant and seal it in the air conditioned room in the morning, not on the boat, and the fog is really not a problem. Vale, and practise the white balance on the house reef first.

And don't expect anything usable from dive one. Look at the turtle with your eyes first.

Reading this whilst it's 9 degrees and sideways rain in Edinburgh. The Maldives. Honestly. Have a brilliant trip and post the turtle when you're back!