Not having been raised near an ocean, but rather ponds and lakes... I would at first glance call these muscles.  I don't know their proper name.  But as I looked at them, I realized how much this was like my life used to be - and still is in a way.  Clinging on for dear life, perhaps depending on others to hold me up in my spot.  Afraid of letting go that I might sink to the bottom and never come back up.  But today, I'm not so afraid of anything but I certainly don't underestimate the power of my friends and family.

To me, these shells are also symbolic of city living - all jammed in to one place with barely any room to breathe, yet still necessary to help make the world go 'round.  Just my observation, and yeah... the water really was that color in the Bahamas.