Variants of a mold are catalogued separately, so each one has its own sets and minifigs. Check these too if something you expect is missing here.

• 6052 Boat Hull Section, Small Stern 14 x 12 x 5 1/3, Base Sub-part of this part
• 6053 Boat Hull Section, Small Stern 14 x 12 x 5 1/3, Top Sub-part of this part