sea·mark 
(sēmärk′)
(sēmärk′)n.
1. A landmark visible from the sea, used as a guide in navigation.
2. A buoy or channel marker.
3. A transient natural feature, such as a clump of floating vegetation or a flock of birds in flight, that gives a rough indication of the proximity or direction of land, used as a navigational guide in some traditional seafaring cultures.
- in (one's) own right
- in one's own right
- in (one's) pocket
- in one's pocket
- in (one's) tracks
- in one's tracks
- in (one's) wheelhouse
- in one's wheelhouse
- in one/the same breath
- in on the kill
- inoperability
- inoperable
- inoperably
- inoperative
- inoperativeness
- inoperculate
- inopportune
- inopportunely
- in order that
- in order to
- inordinacy
- inordinate
- inordinately
- inordinateness
- inorganic