mooring pole; mooring post
A pole or post on a dock or shore used to tie up a boat.
I tied the boat securely to the mooring pole.
Common mixed kanji-kana spelling; the kana portion avoids rare kanji 舫.
Full kanji spelling using 舫, which is uncommon and may be unfamiliar to many readers.
Compound of もやい (mooring, from verb もやう 'to tie up a boat') and 杭 (くい, 'stake, post').