7.60 avg 10 episodes 7.4 → 7.5 42 min avg
| # | Title | Rating | Votes |
|---|---|---|---|
| 1 | The Mermaid Discovery | 7.4 | 1,040 |
| 2 | The Lure | 7.5 | 809 |
| 3 | Interview with a Mermaid | 7.5 | 691 |
| 4 | On the Road | 7.8 | 637 |
| 5 | Curse of the Starving Class | 7.6 | 586 |
| 6 | Showdown | 7.5 | 539 |
| 7 | Dead in the Water | 7.9 | 522 |
| 8 | Being Human | 7.5 | 495 |
| 9 | Street Fight | 7.8 | 497 |
| 10 | Aftermath | 7.5 | 489 |
7.69 avg 16 episodes 7.6 → 8.2 42 min avg
| # | Title | Rating | Votes |
|---|---|---|---|
| 1 | The Arrival | 7.6 | 439 |
| 2 | The Wolf at the Door | 7.7 | 374 |
| 3 | Natural Order | 7.7 | 359 |
| 4 | Oil & Water | 7.8 | 369 |
| 5 | Primal Instincts | 7.5 | 356 |
| 6 | Distress Call | 7.7 | 342 |
| 7 | Entrapment | 7.8 | 335 |
| 8 | Leverage | 8.4 | 374 |
| 9 | No North Star | 7.6 | 313 |
| 10 | All In | 7.5 | 279 |
| 11 | Mixed Signals | 7.5 | 273 |
| 12 | Serenity | 7.6 | 268 |
| 13 | The Outpost | 7.5 | 265 |
| 14 | The Last Mermaid | 7.4 | 261 |
| 15 | Sacrifice | 7.6 | 267 |
| 16 | New World Order | 8.2 | 325 |
8.09 avg 10 episodes 7.9 → 8.5 42 min avg
| # | Title | Rating | Votes |
|---|---|---|---|
| 1 | Borders | 7.9 | 297 |
| 2 | Revelations | 8.0 | 266 |
| 3 | Survivor | 8.0 | 244 |
| 4 | Life and Death | 8.0 | 248 |
| 5 | Mommy and Me | 7.9 | 245 |
| 6 | The Island | 8.2 | 246 |
| 7 | Northern Exposure | 8.2 | 248 |
| 8 | 'Til Death Do Us Part | 7.9 | 232 |
| 9 | A Voice in the Dark | 8.3 | 252 |
| 10 | The Toll of the Sea | 8.5 | 340 |
