It depends which NCIS you are referring to. CBS broadcasts NCIS, NCIS: Los Angeles, and NCIS: New Orleans. NCIS is aired on Tuesdays 8/7c. NCIS: Los Angeles is aired on Mondays 10/9 c. NCIS: New Orleans is aired on Tuesdays 9/8c.
Whereas groins are built to change the effects of beach erosion, jetties are built so that a channel to the ocean will stay open for navigation purposes. They are also built to prevent rivermouths and streams from meandering naturally.
The Cape Hatteras Lighthouse protected the waters off of Hatteras Island for over a hundred years, but by the early 1990s, the towering structure was faced with a new problem: beach erosion.