a border, edge, limit ; boundary / a side / a rim / a shore

freeboard

aboard, on board

outboard motor / speedboat, outboard (vessel fitted with an outboard motor)

outboard (situated outside the hull of a vessel)

overboard

by, beside, next to, on the side of, on the edge of / on the verge of, on the brink of

(nautical) to tack, to change tack, to switch tack, to put about / (figuratively) to change sides, to box the compass / (figuratively) to switch teams (to change one's sexual orientation)

logbook

logbook