distinguish between jetties and groins

[mattyschell]

Is it too in the weeds to note that groins are being included in the hydro structure - jetty subtype?

Engineers build jetties at the mouth of a river or harbor to keep the channel open.

Engineers build shorter, fatter groins perpendicular to the shoreline, commonly to prevent beach erosion.

Most, if not all, of the jetties captured in planimetrics are in actual fact groins. Here is one possible exception.

These are all groins.

[mattyschell]

Florida has legit jetties