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.
Erosion is a process, not a problem. Beaches are dynamic and natural. Buildings, bridges and roads are static. The problem occurs when there is a static structure built on a dynamic, moving beach. If buildings and roads were not built close to the shore, we would not have to worry about shoreline structures or sand erosion. Responses to Erosion Seawalls