礁 is a Japanese kanji written with 17 strokes, listed here under the keyword “reef”. It is built from 石 (stone) and 焦 (char). In Remembering the Kanji by James W. Heisig it is frame 600.
On KumiJi Glyph Explorer, open the parts search and type “stone” + “char”. 礁 is among the results, together with every other character containing the same shapes.
Open 礁 in the interactive kanji search
to expand every part down to its smallest pieces, add your own names and mnemonic stories,
or search for other characters by their parts.