reef, sunken rock
礁 centers on a rocky formation in water: a reef or a sunken rock, often just below the surface.
礁 combines 石 (stone) with 焦, which likely contributes the sound and the idea of something scorched or burnt, perhaps referring to the dark, jagged appearance of reef rocks.
A stone 石 that looks scorched 焦 rises from the water: that's a reef or sunken rock.
For ショウ, imagine a reef just below the surface that you can only see when the sun is low and casts a long shadow: shadow -> ショウ, and the shadow reveals the hidden reef.
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running aground; being stranded; grounding; beaching
coral reef
reef
atoll; circular coral reef
reef
reef; sunken rock
artificial fish reef
barrier reef
stranded ship; ship that has run aground
to run aground; to strike a rock; to be stranded on a reef
barrier lagoon; coral-reef lagoon
fringing reef
refloating; getting off a reef; getting off the rocks
fish reef; reef where fish live and breed