Why rock pooling suits a family afternoon so well

Nowhere else on the British coast gives you so much wildlife for so little equipment. A shallow pool on a low spring tide can hold a dozen species within arm's reach, and you need nothing more than wellies, a plastic tub and a spare hour. Rock pools are also remarkably forgiving: their inhabitants are used to being bashed by waves, and children can watch, wonder and learn without going near deep water. The trick is to leave every pool exactly as you found it, and to make the looking itself the entertainment.

Plan around the tide, not the clock

The best window is the two hours either side of low water, when the tide has drawn back off the rock platform. Check a tide table for your actual beach rather than the nearest town, because a headland can shift times by half an hour or more, and give spring tides priority — their bigger range exposes the lower shore where the richest life lives. Avoid the hours around high water altogether.

Estuaries need a little extra respect. Their tides can move faster than you walk, muddy channels can be deeper than they look, and water quality dips after heavy rain, so wait a day or two after a downpour before letting children paddle. Pack wellies with proper grip, a shallow plastic tub, a magnifier, a small first aid kit, water, hats, sun cream and a flask. A plastic wallet and a printed spotter sheet complete the kit.

A spotter sheet that keeps children looking

Skip the naming contest and encourage tallying instead. Children stay engaged far longer when they are counting than when they are being quizzed. Split the sheet into three columns: common finds, less common finds, and a "draw what you saw" box at the bottom.

• Easy ticks: periwinkles (flat and rough), limpets, barnacles, common mussels, top shells, sea slaters and shore crabs.
• Look closer: beadlet anemones, brittlestars, prawns, blennies, gobies, dog whelks, edible crabs and velvet swimming crabs.
• Seaweed without picking: bladderwrack with its air-filled bubbles, kelp, coralline and sea lettuce.

Laminate the sheet or slip it into a plastic wallet and use a whiteboard pen, so one sheet lasts a whole season. Photographs and sketches count as finds — nothing needs to go home in a bucket.

The gentle hands rules

Fragile marine life copes with being looked at; it struggles with being collected, dried out and forgotten. A few habits make a big difference.

• Roll a stone towards you, low down and over the pool, so anything underneath drops back into the water and the stone can be replaced the same way up.
• Never move a wedged or oversized boulder. Nothing beneath it is worth crushed fingers or a flattened habitat.
• Use wet hands, or better still a tub of seawater and the magnifier. Dry skin and dry shells are a bad mix for small crabs and anemones.
• Keep creatures in a shallow tub of water in the shade for a few minutes at most, and return them to the exact pool they came from.
• Never prise limpets off rocks, and leave seaweeds attached by their holdfasts.
• Replace each stone before moving on. You should expect to find less than you did a moment before; that is the point.

Staying safe on rock and mud

Wet green seaweed is as slippery as ice, and rock platforms often end in a sudden drop. Keep children within sight and reach, never let them turn their backs on the sea, and set a firm rule that nobody goes deeper than welly depth. Estuary mud is not a play surface: it can be chest-deep and holds like glue, so stay on firm sand and marked paths. Weever fish and jellyfish deserve a warning too — shuffle your feet rather than stamping, and rinse any sting with seawater rather than fresh water.

Carry plasters for barnacle grazes, tell someone where you are going and when you will be back, and remember that mobile signal is patchy along many shores. In an emergency, call 999 or 112 and ask for the Coastguard.

History, harbours and a plate of local food

The shore you are crouching on has been worked for centuries. Victorian families went rock pooling in their Sunday best during the aquarium craze of the 1850s, and the same estuaries were busy with oyster beds, mussel layings, ferries and wherries long before that. Old stone quays, ferry steps and seaweed-gathering rights are still there if you know what you are looking at.

Afterwards, eat like the coast does. Marsh samphire is at its best in July and August; mussels, cockles, oysters, crab and brown shrimp are usually best bought from a harbour shop or fishmonger rather than foraged yourself, since shellfish gathering is regulated and some beds are closed. If you do pick samphire, take only a little, snip above the root, and only where it is plentiful and access is permitted. Chips on the harbour wall, eaten while the tide turns, is the proper ending to a rock pooling day.