Chart No. 1 · Q (US suppl.)
Daybeacon (dayboard)
Buoys & beacons
An unlit fixed mark with a shaped dayboard — triangles and squares echo nun and can meanings.
What it means
US charts show daybeacons — piles carrying shaped dayboards — as small triangle or square symbols: triangular boards (red, even numbers) match nuns, square boards (green, odd numbers) match cans.
Why it matters
Dayboards do the work of buoys in shallow US channels like the ICW. Same memory aid applies: red triangles one side, green squares the other — and 'red right returning' in IALA B.