舟

zhōu boat

Component (a building block) — not the same thing as a radical or a sound component. · 6strokes

舟 left — As a left-side component the last horizontal stroke is written as a rising stroke.
舟 top — 在「盘」上部作简化写法，完整保留 6 画。

Kangxi radical no.137 · 6strokes — The 214 Kangxi radicals

Filed under it in a dictionary. That is a lookup convention — it does not mean it is the only part the character is built from.