1. Existing or occurring beneath the surface of the water

2. Hard outer covering of marine mollusks

3. Imaginative or fanciful ideas, often featuring mermaids

3. Limbs that help mermaids steer and propel through water

4. To produce melodious sounds with the voice, like a mermaid

5. Valuable items often associated with underwater adventures

6. The alternating rise and fall of the sea

6. A fish-like lower part of a mermaid's body

7. Traditional stories or tales, often featuring mythical creatures like mermaids

8. Hard, colorful skeleton secreted by marine polyps

9. To fill with great delight, like a mermaid's presence

10. Daily event when the sun disappears below the horizon

11. Sound and spray caused by an object entering water forcefully

11. A seductive or enchanting woman, often associated with mermaids

12. Rhythmic disturbances of the ocean's surface

13. Aquatic plant-like algae that grows in the sea

14. Color often associated with the depth of the ocean that mermaids inhabit

15. Successions of images, emotions, and sensations that occur during sleep, often intertwined with mermaids

16. Protective coverings on a mermaid's body

17. Hard protective coverings found on the beach

18. Lower limbs that mermaids lack

19. To move through water using limbs or a tail, as mermaids do