Minecraft wiki entry for Ocean_Ruins, associated text: A ruined village partially generated on land.
Ruins generated on an island.
An ocean ruin completely generated on a hill near the water.
A ruined village generated on frozen ocean and beaches.
Ruins generated on land in Bedrock Edition, note that water generated above the chest.
Part of a ruin generated on a windswept hills. The rest of the ruins are in the ocean below. A Village can be seen as well.
A ruined village that generated on land in Java Edition, note that a loot chest is visible and is not waterlogged unlike in Bedrock Edition.
Underwater ruins generated on land.
Underwater ruins generated intersecting an ocean monument, exposing the treasure room.
Underwater ruins with two chests, with a couple of blocks separating them.