In the submerged world surrounding Fort Jefferson in the Dry Tortugas, the walls of this historic fortress reveal a captivating scene as they crumble into the aqua waters. Here's a vivid description of this underwater spectacle:

---

**1. **Sunlit Depths:**
   Descending beneath the surface, the waters surrounding Fort Jefferson open up to reveal a sunlit aquatic realm. The sunlight filters down in radiant beams, creating a play of dappled light that adds an ethereal quality to the underwater environment.

**2. **Crumbling Masonry:**
   The aging walls of Fort Jefferson come into view, their weathered and crumbling masonry telling tales of bygone eras. The fort, which once stood tall and proud, now gracefully yields to the relentless forces of time and the sea.

**3. **Soft Coral Drapery:**
   Soft corals and sea fans drape over the fort's walls like underwater tapestries. Their delicate tendrils sway with the gentle currents, adding a touch of elegance to the rugged remnants of history.

**4. **Historical Echoes:**
   The underwater scene is a fusion of history and nature. The fort's walls, now submersed, become a canvas for marine life, and schools of fish weave through the gaps in the crumbling structure, creating an animated and living tableau.

**5. **Aquatic Symphony:**
   Fish of various shapes and sizes navigate through the submerged walls, their movements orchestrated into a natural symphony. The walls, once silent witnesses to history, now hum with the vibrant energy of underwater life.

**6. **Bubbling Remnants:**
   As portions of the fort crumble into the water, bubbles rise in a gentle ascent. These bubbling remnants are a subtle reminder of the ongoing transformation, a harmonious exchange between the historical artifacts and the marine ecosystem.

**7. **Sunken Architectural Details:**
   Architectural details of the fort, now submerged, come into focus. Arches, alcoves, and other remnants create a hauntingly beautiful underwater landscape, where the intricate details of the fort's design are softened by the embrace of the sea.

**8. **Swaying Sea Grass:**
   Swaying sea grass at the base of the crumbling walls adds a touch of tranquility to the scene. The grass undulates with the rhythm of the water, providing a serene backdrop to the fort's gradual descent into the underwater realm.

**9. **Clarity and Visibility:**
   The clarity and visibility underwater allow for an unobstructed view of the fort's deterioration. Every crack, crevice, and fallen stone is visible, creating a poignant and intimate portrayal of the fort's interaction with the marine environment.

**10. **Timeless Elegance:**
    The crumbling walls of Fort Jefferson take on a timeless elegance in their underwater setting. The scene is a poignant reminder of the inexorable passage of time, where history and nature entwine to create a captivating and ever-changing underwater masterpiece.