We asked our readers to send in their best pictures on the theme of "ripples". Here is a selection of the photographs we received from around the world.
Jiri Dvorak
Jiri Dvorak photographed ducks in London.
Łukasz Wojtylak
Łukasz Wojtylak: “Flowers by the city pond in Niepołomice, Poland. In the background, fish are catching insects in the sunlight.”
Erin Stenzel
Erin Stenzel: “A Red-Striped Ribbon snake cooling off and making some waves at Ladybird Johnson Wildflower Center in Austin, Texas.”
Andrew Martin
Andrew Martin: “Ripples in the sand under Weston-super-Mare pier, giving something of a solar flare vibe.”
Kathlene Persoff
Kathlene Persoff: “Strong Atlantic winds at Palmetto Dunes Beach on Hilton Head Island, South Carolina, created graceful ripples in the sands.”
Chris Tudor
Chris Tudor: “Rhythmic patterns on the trunk of a mature palm tree in Puerto del Carmen, Lanzarote.”
David Robinson
David Robinson: “On a bustling shopping street in central London a reflection of pedestrians creates the impression of urban ripples.”
Matthew Logan
Matthew Logan: “The ripples formed from the water dripping off the paddle of the canoeist makes a perfect arc.”
Quintin Quinn
Quintin Quinn photographed ripples in the sand.
Shauna Dalziel
Shauna Dalziel: “The sky, the sea, the sand all rippled at the Newton Shore, Ayr. We stood and bathed in the glorious sunset.”
John Dawson
John Dawson: “I took a train to Dunbar from Edinburgh, as I had heard there was a lot to see around the harbour area. What I had heard was correct - spent the whole day there.”
Iain Shaw
Iain Shaw: “Clear water ahead. Goslings kicking up a storm.”
Paul Sullivan
Paul Sullivan: “Droplets from a dock line in Pigeon Cove, Rockport, Massachusetts.”
Lee Slater
Lee Slater: “I missed Sarah's impressive dive into Blue Lake, Central Otago, but caught this fine set of ripples instead. This lunar-like landscape used to be one of New Zealand's deepest gold mines.”
Fiona MacCallum
Fiona MacCallum: “East Quay, Wells -next-the-Sea, north Norfolk. I caught the ripples at dusk as a dinghy went past.”
Kevin Privett
Kevin Privett: “Ripples in the fabric of space-time caught on camera; or is it just crazy mirrors on Southwold pier?”
Jenny Retzler
Jenny Retzler: “Ripples on flooded fields around Coniston Water, Lake District.”
Jane Luetkens
Jane Luetkens: “Before steering this insect towards a lily pad and safety, I had to admire the ripples it made on the water.”
Henry Szwinto
Henry Szwinto: “Sunset at Setley Pond, New Forest, Hampshire.”
Miriam Simmons
Miriam Simmons photographed a swimmer at Walpole Bay in Kent.
The next theme is "On top of the world" and the deadline for entries is 11 June 2024.
The pictures will be published later that week and you will be able to find them, along with other galleries, on the In Pictures section of the BBC News website.
Jiri Dvorak
Łukasz Wojtylak
Erin Stenzel
Andrew Martin
Kathlene Persoff
Chris Tudor
David Robinson
Matthew Logan
Quintin Quinn 
Shauna Dalziel
John Dawson
Iain Shaw
Paul Sullivan
Lee Slater
Fiona MacCallum
Kevin Privett
Jenny Retzler
Jane Luetkens
Henry Szwinto
Miriam Simmons