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.

• 2538a Boat, Mast Section Top 16 H with 4 stud holes at bottom, Without Bottom Nubs Mold of this part
• 2538b Boat, Mast Section Top 16 H with 4 stud holes at bottom, With Bottom Nubs Mold of this part