How to Take Underwater Photos: A Photographer’s Field Guide

Practical Guide to Underwater Photography

By William Drumm, underwater photographer and ocean ambassador

I have spent most of my professional life with a camera underwater. I have shot the Billie Eilish “Hit Me Hard and Soft” album cover. I have photographed bull sharks at Cabo Pulmo, humpback whales in Tonga, blue sharks in the open Pacific, crocodiles in Banco Chinchorro, and tens of thousands of toad tadpoles in a remote British Columbia lake.

In all of that work, I have learned this: underwater photography is not difficult because of the gear. It is difficult because the medium is fundamentally different from anything else. Light behaves differently. Color behaves differently. Subjects behave differently. Your body works differently.

Most online “how to take underwater photos” content treats the topic like it is the same as land photography with a waterproof case. That is wrong. The medium changes everything, and the photographers who get good get good by understanding the water first and the gear second.

This guide is written for someone starting out or shooting at an intermediate level who wants to get better. Not just buy more gear. There is a difference, and the gap between the two is where most underwater photography careers stall.

Here is what I cover:

• What you actually need to take underwater photos
• The five settings that matter most
• Why composition underwater is different (and what to do about it)
• How to deal with light underwater
• Backscatter, the single most common amateur mistake
• Subject behavior matters more than gear
• How to edit underwater photos
• Common beginner mistakes

What You Actually Need to Take Underwater Photos

Before any settings or technique, the gear question. I will not turn this into a buying guide because you can find a thousand of those, and the people who write them mostly make money on affiliate links. I will tell you what works at different levels and what I personally use.

Smartphone (entry-level honest take)

Modern iPhones and Pixels are water-resistant to a couple of meters under perfect conditions, and Apple specifically does not warranty water damage. If you want to take underwater pictures with a phone, get a dedicated underwater housing case for it. SeaLife, ProShot, and Diveroid all make decent ones. Your photos will be limited – small sensor, few manual controls in the stock app, color loss correction has to happen in post – but for snorkel trips and shallow tropical water, a phone in a proper case will get you respectable images.

What a phone cannot do: shoot at depth, handle low light, capture fast-moving subjects without motion blur, deliver the dynamic range to recover blue water properly in post.

Action cameras (GoPro, DJI, Insta360)

A GoPro will produce usable images for most casual diving and snorkeling. Wide field of view, water-resistant out of the box to 10 meters or so, and you can put it in a dive housing for deeper. They struggle with low light, the small sensor limits dynamic range, and the wide angle distorts portraits. But for documenting a trip or creating social content while you are still learning, they are fine.

If you are shooting GoPro underwater, make sure you are shooting with the proper serttings. Color loss starts at three meters down and gets dramatic by ten. Setting the correct white balance and enabling the professional settings helps reduce this. Many people will suggest shooting with a red filter on your underwater housing. I have had mixed results with these. Often the images end up overly purple and artificial looking. Better instead to use the best in-campera settings. The newer GoPros also have HyperSmooth stabilization that genuinely helps with hand-held movement underwater.

Insta360 does a really good job with white balance. Often the automatic or underwater white balance settings on the newer Insta360 cameras look great right out of the camera.  

Compact and mirrorless cameras in housings

This is where serious underwater photography starts. Compact cameras like the Sony RX100 series, the Canon G7X, and the Olympus TG-6/TG-7 in their proper underwater housings will produce work that is easily good enough for stock licensing, fine art prints, and most editorial use. Investment range typically: $1,500-$3,000 for camera plus housing plus a basic strobe. I shot with a Sony RX100MII in a Nauticam housing when I was first getting started and it was a perfect setup for me. The video especially looked great, and I kept it as a backup camera for years after upgrading. 

Mirrorless setups in housings are the modern professional standard. Sony A7 series, Canon R series, Nikon Z series, OM System OM-1, and Panasonic GH series all have excellent housing options from companies like Nauticam, Marelux, Aquatica, and Ikelite. Investment range: $5,000 at the entry end to $15,000+ for a full pro rig with two strobes or video lights and multiple lens ports. 

What I personally shoot with

I currently shoot a Canon R5 and R5 Mark II in a Marelux housing. My lens kit:

• Canon RF 28-70mm f/2.0 – my workhorse for wide and standard work, paired with the Marelux 230mm dome port
• Canon RF 15-35mm f/2.8 – for true wide angle reef and pelagic work, used with both the 230mm and 180mm dome ports depending on subject or conditions
• Canon RF 100mm f/2.8 macro – for close-up work, paired with the Marelux macro port

Before the Canon system I shot Lumix GH4 and GH5 cameras in Nauticam housings for years. My tadpole images, some of the early shark work, and a lot of historical content was made on those cameras. They produced beautiful images and video. The medium is more forgiving than the gear discourse suggests. These cameras are fine for photography, but really shine in video capture. 

What this means practically: if you are at the GH4/GH5 stage of investment, you are not held back by gear. You are held back by technique. Shoot for two more years on what you have before you upgrade. Most of the photographers I see plateau at intermediate level do so because they keep buying cameras instead of getting in the water more.

What about strobes and lights?

Strobes (underwater flashes) and continuous video lights are the second-biggest determinant of image quality after the camera-and-housing combination. Without them, you are at the mercy of natural light, which falls off exponentially with depth and shifts dramatically toward blue.

Modern cameras are far better with manual white balance and color range (gamut) than earlier makes. During the day I shoot 80% or more without any additional light. Having more things to mess with often takes your attention off the subject, and I am usually content with shooting manual white balance (for video) to capture an authentic looking scene.

When I do use lighting, I often use video lights instead of strobes. I am a hybrid shooter, typically capturing photos and videos on one dive. Strong video lights brings back colors when needed and allows for hybrid shooting. When using artifical light, two video lights or strobes are better than one because you can light a subject from both sides and eliminate harsh shadows. Single-light setups produce more directional, dramatic lighting which is sometimes what you want. Most working pros carry both options.

Brands worth knowing: Inon, Sea & Sea, Retra, Marelux, Keldan, Ikelite. Price range from about $400 per strobe at the entry end to $1,500+ for top-tier units.

The Five Settings That Matter Most

Camera settings underwater are not magic. They are the same five things that matter on land – white balance, shutter speed, aperture, ISO, and focus mode – just dialed in for a different medium.

White balance

Water absorbs red light first. Going down, the world progressively loses red, then orange, then yellow, until everything turns blue-green. If you shoot with the camera set to auto white balance, your photos will come out blue or green and the auto correction will fight you in post. However, with modern cameras and shooting raw, auto white balance usually works just fine for photos. For video, you will almost always want to shoot manual as fixing the white balance in post can be impossible. 

What I do: I shoot RAW so I can correct white balance fully in post-processing. If you are shooting JPEG (not recommended), set a custom white balance using a white slate or your own hand at depth. Many cameras let you save custom white balance presets for different depths.

If you are using strobes, the strobe light is full-spectrum and restores the color the water has stripped out. Auto white balance works much better with strobe lighting because the camera is reading the strobe, not the ambient blue water.

Shutter speed

Two rules:

• For ambient-light shots without strobes: 1/125 second is your starting floor. Slower than that and you will get motion blur from your own movement and the subject’s. The water is always moving you slightly, even when you think you are still. Usually you will want to shoot higher than this to capture sharp images. I usually try to stay at at least 1/250 second.
• For strobe-lit shots: shutter speed controls ambient exposure (the blue water background) while strobe power controls the foreground subject exposure. This is one of the most powerful concepts in underwater photography. Slower shutter = brighter blue background. Faster shutter = darker, more dramatic background. Adjust for the look you want.

For fast subjects (sharks, dolphins, bait balls), 1/500 to 1/1000 second if you can manage it. For slow subjects (corals, anemones, sleeping turtles) you can drop to 1/60 if you have stabilization.

For shooting underwater portraits and people, I usually shoot 1/250 second to 1/400 second. When scuba diving you can get away with slower shutters as you and the subject are usually more stable. When freediving, I try to stay above 1/400 second.  

Aperture

Apertures behave a little differently underwater because the dome port adds a virtual image plane in front of your camera. Practical guidance:

• Wide angle (15-35mm): f/5.6 to f/11 for sharpness across the frame. Wider apertures produce soft corners with most dome ports. However wide angle images are usually easier to capture sharp images.
• Standard zoom (28-70mm range): f/5.6 to f/8 for portraits and mid-range work, f/8 to f/11 if you want greater depth of field. For pool work I often prefer a softer background, and will got as low as f/2.0 depending on the subject’s distance and the desired result.
• Macro (100mm or similar): f/11 to f/22 for shallow depth of field control. Macro requires high apertures because magnification reduces apparent depth of field dramatically.

Diffraction does start kicking in around f/16 on most modern sensors, so f/22 macro work has a slight softness penalty. Worth it for the depth of field benefit at 1:1 magnification.

ISO

Push higher than you think you should. Modern full-frame sensors handle ISO 1600-3200 cleanly, and ISO 6400 is usable. Underwater, the choice is almost always between higher ISO and motion blur. A noisy sharp photo can be cleaned up in post. A blurry low-noise photo cannot be saved.

My typical underwater starting ISOs:

• Bright tropical water, sunny day: ISO 200-400
• Mid-depth or overcast: ISO 800-1600
• Deep, dim, or temperate water: ISO 1600-3200
• Cave, wreck interior, or other dark conditions: ISO 3200-6400 with strobes
• When night diving, depending on your lights, you might be able to shoot at very low ISO especially if shooting macro

Focus mode

Autofocus underwater is harder than autofocus on land. Less light, lower contrast, particles in the water that the AF system tries to grab onto. What I use:

• Continuous AF for moving subjects: sharks, fish, anything traveling. Set the camera to track the subject.
• Single AF for portraits and macro: lock focus on the eye, hold, recompose if needed.
• Manual focus for difficult conditions: extreme low light, low visibility, when the AF cannot find anything to grab. Pre-focus to expected subject distance.

On the Canon R5 and R5 Mark II, eye-detection AF works on fish and marine mammals about 70% of the time. When it locks, it locks well. When it does not, switch to single-point AF and put the point on the eye yourself.

Shooting modes: manual, shutter priority, and auto ISO

Most underwater photographers default to Manual mode because that is what the books and the YouTube tutorials recommend. Manual works great when the light and the distance between you and your subject are constant – reef scenes, macro work where you are not moving much, slow-moving subjects in good light. You dial in your aperture, shutter speed, and ISO once, and shoot.

But underwater conditions rarely stay constant. Animals move closer and further, you swim around the scene, and the light changes dramatically as you tilt the camera up toward the surface or down into shadow. In those situations, Manual will leave you constantly chasing your settings while the moment passes.

This is where Shutter Priority becomes the better choice. You set the shutter speed (fast enough to freeze the subject), and the camera handles the aperture. When a sea lion swims at your dome port and then away, when you are tracking a school of fish, when you are repositioning your camera around a subject, Shutter Priority gives you one less thing to think about.

For my own shooting, I am roughly 70 percent Shutter Priority and 30 percent Manual. Shutter Priority for active wildlife and dynamic compositions; Manual for the times when I can plan the shot and the conditions are stable.

A note on Auto ISO

Auto ISO is usually a good option to pair with either mode. It lets the camera adjust ISO when light changes – swimming from a shallow sunlit reef into a deeper shadowed area, for example – while you maintain control of the more important variables.

The catch: Auto ISO performance depends on your camera and the available light. Modern mirrorless bodies with good high-ISO performance (the Canon R5, Sony A7 series, Nikon Z bodies) handle Auto ISO well in most underwater conditions. Older cameras or cameras with smaller sensors will push the ISO higher than is ideal, introducing noise into shadow areas. If you are shooting a camera that struggles above ISO 1600, you may be better off setting ISO manually and accepting some underexposed frames rather than letting Auto ISO push the noise floor up.

Test it on your specific setup before relying on it for an important dive.

Why Composition Underwater Is Different

On land, you stand on a fixed platform and the world is mostly static. Underwater, you are floating in three dimensions, your subject is moving in three dimensions, and the medium between you and the subject affects every photo.

A few principles that I have come to rely on:

Get closer

The single most common amateur mistake. Water reduces contrast, color, and detail with every meter of distance between camera and subject. A shark photographed from 5 meters away looks soft and washed out. The same shark photographed from 1.5 meters away pops.

Aim to be one to two meters from your subject for most work. For wide angle, you want to be even closer – sometimes inches away from the foreground element with the wider scene behind it. The rule of thumb: get closer than feels comfortable, then get closer again.

Shoot up, not down

When you photograph a subject from above, you are shooting against the seafloor or murky water. Boring background. When you photograph the same subject from below, you are shooting against the water column rising to the surface. Often you will see sun rays or open blue. Always more dramatic.

Get below your subject when you can. Even shooting level with the subject is better than shooting down. Most beginners spend their first hundred dives shooting straight down at the reef. Stop doing that.

Negative space and the water column

Underwater you have a unique compositional element that does not exist on land: the water column. Open blue or green water surrounding your subject. This is incredible negative space. Use it.

The shark with empty blue around it. The ray with sand below and water column above. The diver silhouetted against sun rays. These compositions only work underwater because the water column gives you a clean canvas. Let it.

Rule of thirds applied to depth

The standard rule of thirds (subject on intersecting third lines) still works, but underwater you have a third dimension to think about. Where is the subject in the frame, and where is it in depth? A shark cutting diagonally across the frame from foreground to background creates dynamic depth. A shark perfectly parallel to the sensor plane is flat.

Use diagonal lines, layered foreground/background relationships, and depth-staggered subjects to create three-dimensional images.

How to Deal With Light Underwater

Light underwater is a complete physics problem. The sooner you understand the physics, the sooner you start making photos that look right.

The basics of underwater light

Light loses intensity as it travels through water. By 10 meters down, you have roughly a quarter of the surface light. By 30 meters, you are working in twilight. By 60 meters, not that many of us go that deep, it is functionally dark in even the clearest tropical water.

Color loss tracks depth too. Red disappears in the first 3-5 meters. Orange in the first 10 meters. Yellow by 20 meters. By 30 meters, the world is essentially blue with hints of green.

This means:

• Shallow ambient-light photography is the easiest to start with – you have light and color
• Mid-depth ambient work needs more thought about white balance and exposure
• Deep work essentially requires artificial light (strobes or video lights) to preserve color

Backscatter, the Single Most Common Amateur Mistake

Open Instagram and look at amateur underwater photos. Half of them have white spots, sparkles, and dots scattered across the image. That is backscatter, and it is what happens when your strobe light hits suspended particles in the water and lights them up between your subject and the lens.

Some amount of particulate is in the water everywhere, even in the clearest tropical visibility. The cleaner the water, the less you see it. The murkier the water, the more aggressive the backscatter becomes.

How to reduce backscatter

• Get closer to your subject. Less water column between camera and subject = less particulate to light up. This alone solves half of all backscatter problems.
• Pull your strobes outboard. Keep them away from the camera-to-subject axis. The particulate that gets lit up sits in a cone in front of the lens; angle the strobe light to come from outside that cone.
• Shoot in cleaner water when you can. Some sites have notorious silt loads. If you are still learning, go to clearer water until your technique is solid.
• Use a snoot (a narrow attachment that focuses strobe light into a tight beam) for macro work. Stops light from spilling into surrounding water.
• Lower strobe power. If your subject is close enough, you may only need a fraction of strobe power. Less light means less particulate gets lit.

Cleaning up backscatter in post

Some backscatter is removable in post-processing. The Lightroom spot removal tool, the Photoshop healing brush, and AI-based tools like Topaz can all clean up scattered dots, especially in clean water column areas.

But removing backscatter is tedious and time-consuming. Far better to prevent it in-camera. The hour you would spend retouching a single image in Photoshop could be the hour you spend repositioning your strobes correctly on the next 50 dives.

Subject Behavior Matters More Than Gear

Here is the secret most working underwater photographers know that beginners do not. The animals in front of you are reacting to you in real time, and 80% of getting good underwater photographs is reading their behavior correctly.

A shark that is curious will swim toward you. A shark that is wary will swim past you in a wide arc. A shark that is agitated will arch its back, tilt its pectoral fins down, and approach with measured movements. The same animal will give you completely different photographs depending on which of these states it is in.

General principles

• Slow down. Frantic movement spooks almost everything underwater. Move like you have all the time in the world.
• Do not chase. The moment you swim toward a subject, they will swim away. Position yourself where they will pass through and wait.
• Make yourself smaller. Tucking your fins, pulling your strobes in, presenting a smaller silhouette – all of this reduces threat perception.
• Watch the eyes. An animal looking at you is reading you. An animal not looking at you is comfortable enough to ignore you.
• Respect personal space. If a subject moves away, give them more distance, do not chase. They will often come back when you stop pursuing.

Specific subject notes

Sharks: Most sharks are curious or indifferent rather than aggressive. They circle to assess you. The best photographs come when they decide you are interesting enough to investigate. This often takes 10-30 minutes of presence in the water before they engage. Be patient.

Whales and dolphins: Marine mammals choose whether to engage with you. You cannot make them stay. The best work happens when you are close enough to be interesting but moving slowly enough to be safe. Tonga humpbacks routinely came within meters of me when I held still on a single breath-hold and let them approach.

Reef fish: Most reef fish have a critical distance threshold. Inside that threshold, they flee. Outside it, they ignore you. Learn to identify the threshold for each species and photograph from just outside it.

Macro subjects: Nudibranchs, blennies, shrimp – these are usually patient subjects who do not register your presence as threatening. The challenge is positioning yourself stable enough to make sharp images. Use rocks, sand, or your reef hook to stabilize without damaging anything.

Reptiles (turtles, crocodiles): Reptiles think on a different timescale than mammals. A turtle might tolerate you for 30 minutes if you do not move erratically. A crocodile in Banco Chinchorro will assess you slowly and decide you are not food. Both reward patience.

People (portraits): A subject who is comfortable produces dramatically better photographs than one who is panicking about breath-hold. Spend the first half hour of any portrait shoot just letting the model get used to being underwater. The work that comes after is exponentially better than the work that happens when you start shooting on minute one.

How to Edit Underwater Photos

Underwater photographs almost always require post-processing because the medium fundamentally distorts color and contrast in ways that have to be corrected to render the scene as the eye saw it. There is no shame in this. It is not “cheating.” Land photographers correct exposure, white balance, and contrast on every photograph too. Underwater just requires more of it.

A high-level overview of my workflow (full breakdown coming in a dedicated post):

Step 1: White balance. Always start here. Pull the temperature warmer to compensate for the blue-green cast water adds. Use the eyedropper on a white object in the frame if you have one.

Step 2: Exposure and tonal balance. Lift shadows, recover highlights, set black and white points. Most underwater RAW files come out flat and benefit from contrast added in this stage.

Step 3: Color grading (HSL panel). Boost the saturation of warmer colors (reds, oranges, yellows) that the water has stripped out. Sometimes desaturate the dominant blue or green to push it back from overpowering the frame.

Step 4: Detail and noise reduction. Sharpen for output. Reduce noise from high ISO captures. The order matters – sharpen after noise reduction.

Step 5: Spot removal (backscatter cleanup). Healing brush for visible dots and particulate. Be selective. Some dust adds atmosphere; remove the obvious distractions only.

Step 6: Final polish. Vignetting, subtle dodging and burning, any creative grading specific to the image. Less is more here.

I will publish a dedicated post on Lightroom workflow for underwater photographs. For now, the principle: edit with restraint. The image should look like a great underwater photograph, not like a fantasy painting of one. The most common amateur over-edit is pushing saturation and contrast so aggressively that the image looks artificial. Pull back.

Common Beginner Mistakes I See Constantly

After years of teaching and looking at student work, I see the same handful of mistakes over and over. If you can avoid these, you are already ahead of most people who have been shooting underwater for years.

1. Shooting from too far away. The single biggest mistake. Get closer.
2. Shooting down at subjects on the reef. Shoot up or shoot level. Nothing kills an image faster than a flat top-down angle on a busy reef.
3. Strobes pointed straight forward. Instant backscatter. Pull the strobes outboard.
4. Shooting JPEG instead of RAW. You give up almost all of your editing latitude. Shoot RAW. Storage is cheap.
5. Not setting white balance manually or shooting RAW for ambient work. Auto white balance fights you in post on ambient blue water shots. Either set it manually or shoot RAW and fix it in post.
6. Chasing animals. They will leave. Position yourself well and wait for them to come to you.
7. Treating the camera as the priority. The camera is a tool. The water is the subject. The animal is the moment. The camera is a distant third in importance, but most beginners obsess over it.
8. Not learning to dive well first. You cannot photograph what you cannot reach safely. Dedicated dive practice without a camera, just to learn buoyancy, will make you a better photographer than any new lens. I am serious about this.
9. Not editing, or over-editing. Both extremes hurt the image. Edit with restraint and a clear vision for what the photograph should be.
10. Not getting in the water enough. Two hundred dives a year produces better photographers than ten dives a year with the latest camera. Time underwater is the gear that matters most.

Where to Go From Here

Underwater photography is a craft you can practice for decades and still be learning. I have been doing this work professionally for years and there are still days when I come up from a dive and look at the back of the camera and realize I missed a frame I should have caught. The work is the joy.

A few next steps if this guide was useful:

•  Read my How To Become an Underwater Photographer blog
• Read my deep-dive on underwater photography settings (coming soon – linked when published)
• Read my Lightroom workflow for underwater photos (coming soon)
• Read about underwater portrait photography specifically (coming soon)
• Look at my dive destination guides for places to practice – Cabo Pulmo, Kona, Banco Chinchorro, Mag Bay, and Belize’s Great Blue Hole
• Sign up for my newsletter where I share new work, technique notes, and dive opportunities
• Follow my work on Instagram @williamdrumm
  
  And if you take one thing from this whole guide, take this: get in the water more. The medium teaches you. The gear catches up.

Frequently Asked Questions About Underwater Photography

How do I take underwater photos?

At the highest level: get a camera that works underwater (phone in case, action camera, or a real camera in a proper housing), get close to your subject (closer than feels comfortable), shoot RAW so you can fix color in post, use the right shutter speed for the subject (1/125 minimum for hand-held ambient, 1/250+ for fast subjects), and learn subject behavior so you can predict where animals will be.

What camera is best for underwater photography?

It depends on your level and budget. For casual snorkeling, an iPhone in a proper underwater case will work. For real diving, an action camera like a GoPro is the entry point. Compact cameras in housings (Sony RX100, Canon G7X) start the path to serious work. Mirrorless cameras in housings (Sony A7, Canon R5, Nikon Z series, OM System OM-1, Panasonic GH series) are the modern professional standard. I personally shoot a Canon R5 and R5 Mark II in a Marelux housing.

Do I need a strobe for underwater photography?

Not always. Shallow ambient-light work, silhouettes, sun-ray shots, and pelagic work with large subjects (whales, big sharks) can all be done well with natural light alone. But for reef close-ups, macro work, deep diving, and any shot where you want true color in the foreground, strobes (or continuous video lights) are essential because water strips out warm colors with depth.

What settings should I use for underwater photography?

Starting points: shutter speed 1/125 minimum (faster for moving subjects), aperture f/8 to f/11 for wide angle and standard work and f/11 to f/22 for macro, ISO 200-400 in bright shallow water and 1600-3200 in deeper or dimmer conditions. Always shoot RAW. White balance can be auto if shooting RAW (you fix in post) or custom-set if shooting JPEG.

Why are my underwater photos blue or green?

Water absorbs red light first, then orange, then yellow, then green. By 10 meters down, your photos will look mostly blue or green because that is what is left of the spectrum. Two solutions: shoot RAW and correct white balance in post-processing, or use strobes which provide full-spectrum light and restore the colors water has stripped away.

What is backscatter and how do I avoid it?

Backscatter is the white spots, sparkles, and dots in underwater photos caused by strobe light hitting suspended particles in the water between your camera and the subject. To avoid it: get closer to your subject (less water between camera and subject), pull strobes outboard so the light angle does not hit particles in the camera-to-subject path, shoot in clearer water, and use lower strobe power when the subject is close enough.

Can I take underwater photos with my iPhone?

Yes, with a proper underwater case (SeaLife, ProShot, Diveroid, and others make them). Apple does not warranty water damage even on water-resistant phones, so a dedicated case is essential below a meter or two. Photos will be limited by the small sensor and lack of manual controls in the stock app, but for shallow snorkel work and pool photography, an iPhone in a case will produce respectable results.

How do I get good at underwater photography?

Dive often. Learn buoyancy until it is automatic. Get closer to subjects than feels comfortable. Shoot RAW and learn to edit. Study the work of underwater photographers you admire. Take a course or workshop with a working pro if you can. The single biggest determinant of quality is time in the water – 200 dives per year produces better photographers than 10 dives a year with newer gear.

How long does it take to learn underwater photography?

You can produce respectable images within your first 20-50 dives if you focus on technique. Truly competent underwater photography (the level where you can shoot for clients or stock) is more like 200-500 dives of focused practice. The work is a craft – it does not have a finish line. I have been doing this for years and still learn things on most dives.

Should I take a course in underwater photography?

Yes if you can. A workshop or course with a working pro accelerates the learning curve dramatically because you skip the trial-and-error phase. PADI offers a Digital Underwater Photography specialty. Backscatter, Bluewater Photo, and several individual photographers (Alex Mustard, Tony Wu, others) run workshops at major dive destinations. Even one good workshop will teach you years of technique compression in a week.