Start With the Tide, Not the Camera

The best rock pool photographs are made in the two hours either side of low water on a spring tide, when the widest band of shore is exposed. Check a tide table the night before and pick a low that falls in daylight — a 4am low in January is no use to anyone. Spring tides, the ones following a full or new moon, drop furthest and reveal pools that stay submerged on neap tides.

Weather matters as much as timing. A flat, overcast day is a gift: soft, even light, no hard shadows cutting across the water, and colours on the pool floor that actually read. Bright midday sun is the hardest condition to work in, because wet rock and the water surface bounce glare straight back at the lens. If you can only go at noon, look for pools shaded by a wall of rock or a cliff edge.

Natural Light Beats Flash Every Time

Flash is the single biggest mistake in rock pool photography. Fired at close range into shallow water it produces a hard white hotspot, flattens the texture of the pool floor, and startles animals that are already exposed and vulnerable at low tide. There is no shot worth that.

Work with what the sky gives you instead:

• Shade the pool with your own body or a piece of card to kill surface reflections — this is often more useful than any filter.
• A polarising filter cuts glare from the water surface and lets you see through to the pool bed, revealing anemones and weed you'd otherwise miss.
• On overcast days, raise your ISO to 400 or 800 rather than reaching for flash. Modern sensors handle it comfortably and you keep the natural colour.
• Shoot at f/8 to f/16 for depth of field, but accept a slower shutter speed only when your subject is still. A feeding prawn needs 1/250 second or faster.
• Turn off any autofocus assist beam — it's a small light, but it's still a light in a creature's face.

Get Low, Stay Still, and Use the Pool's Own Frame

The pool is a world seen from above, so the temptation is to shoot downwards. Resist it. Crouch, kneel on a dry mat or lie along the rock so your lens sits at or just below the waterline. This gives you an eye-level view of a beadlet anemone or a blenny resting on a ledge, and it stops your own shadow from falling across the frame.

Keep your hands out of the water where you can. A small waterproof camera or a phone in a housing lets you dip the lens gently beneath the surface without disturbing the pool; a clip-on close-up lens costs little and transforms what you can capture of barnacles, periwinkles and tiny shrimp. Watch your footing as much as your framing — wet weed on angled rock is genuinely treacherous, and a tripod leg planted in a pool crushes everything beneath it.

Never Move an Animal for a Photograph

This is the rule that matters most, and it has no exceptions. Do not lift a limpet from its rock, do not prise an anemone off a stone, do not pick up a crab and place it on a prettier shell, and do not chase a fish into a corner of the pool for a better angle. Every one of those actions costs the animal something, and the resulting photograph is a picture of your interference, not of the shore.

A few practical habits to build:

• If you turn a stone to see what's underneath, put it back exactly as you found it, same side up and in the same position. Many creatures depend on that precise arrangement.
• Keep your hands out of the water where possible, and never handle an animal with warm, dry hands.
• Leave limpets alone entirely. They return to a personal "home scar" on the rock and can be dislodged by the slightest nudge.
• Don't collect shells that are occupied. A hermit crab in a handsome whelk shell is a resident, not a prop.
• Watch where you kneel and where you set your bag. A cushion star or a sea hare is easy to miss and impossible to un-crush.

Patience Reveals More Than Any Lens

Sit down beside a pool and do nothing for five minutes. Your shadow leaves, the ripples settle, and the pool comes back to life. Blennies poke their heads from crevices, prawns drift out from under weed, a hermit crab begins its slow inspection of a new shell. That behaviour — feeding tentacles opening, a fish turning to watch you — is far more compelling than a static portrait.

Return to the same pool across a season, if you can. You'll learn which rocks the crabs favour and where the anemones cluster, and your pictures will improve because you stopped hunting and started watching.

Leave the Pool as You Found It

Before you go, scan your spot: no bag straps trailing in the water, no litter, no displaced weed. Then check the sea, not your screen. Tides turn faster than most people expect, and a rising swell on a rocky shore leaves very little room for error. Tell someone where you're going, carry a phone in a dry bag, and never turn your back on the water. The best rock pool photographers are the ones who come home with dry feet, a full memory card and a shore exactly as they left it.