In the center of Sansara, near some of the oldest sims on the Grid, sits a small, charming island with underwater caverns beneath it. The Cave Rua Water Gardens, pictured below, were designed by Jemma Flora and are lovely to explore. Cleverly tucked under and around the island, the gardens feature a shipwreck, some picturesque ruins, and schools of colorful fish. Rez is on with a ten minute autoreturn if you wish to use the area with photography props.
Staying beneath the waves and following the path to the Southeast, the underwater gardens continue through some protected land to a large open area filled with jellyfish, brightly colored corals, schools of fish, and poses for mermaids. Here and there, you'll find that parts of the garden are available to purchase; sort of a living store area designed by Abby Dawson.
While exploring, I was lucky enough to catch a glimpse of that mythical creature of land, sea, and sky, Ziki Questi, seen in the picture below wearing Alpha Tribe's "Golden Ammonites". (/me grins) Seriously tho', if you haven't visited Alpha Tribe's amazing store and sim, you should. It isn't Mainland but it's still worth a look. ;) Artist and designer Alpha Auer's creations can either be found inworld or in her marketplace store.
The island above the water gardens (photo below) is also worth a visit. Towering trees and well-placed boulders surround a sun-lit glade filled with dragonflies, flowering weeds and ferns, and provide a sense of privacy in an otherwise busy sim. Worn and weathered statuary are set amidst the trees, and couples can find a salsa dance near the ruins at the island's edge.
Underwater exploration is an awful lot of fun in Second Life, and this is a great place to start exploring. You can pick up a free mermaid tail on the marketplace here, and that same store has free breath bubbles. You can also find some free mole-created diving gear on Poseidon Island in the Sea of Fables. There's fixed landing point, but find your way down to the water's edge to the South to collect your gear.
One of my favorite pirate-girl/mermaids is SJ Tucker, who travels through Second Life as Sooj Foxclaw. This lovely Mainland spot reminded me of her, so as you prepare to explore the underwater mysteries, enjoy her delightful song, "Neptune". Happy diving!
"Years ago I came to you
down beneath your ripples
submitting to the mystery
of life beneath the waves."