7.62 avg 10 episodes 7.4 → 7.6 42 min avg
| # | Title | Rating | Votes |
|---|---|---|---|
| 1 | The Mermaid Discovery | 7.4 | 1,015 |
| 2 | The Lure | 7.5 | 792 |
| 3 | Interview with a Mermaid | 7.5 | 675 |
| 4 | On the Road | 7.8 | 622 |
| 5 | Curse of the Starving Class | 7.6 | 569 |
| 6 | Showdown | 7.6 | 525 |
| 7 | Dead in the Water | 7.9 | 512 |
| 8 | Being Human | 7.5 | 485 |
| 9 | Street Fight | 7.8 | 487 |
| 10 | Aftermath | 7.6 | 482 |
7.70 avg 16 episodes 7.6 → 8.2 42 min avg
| # | Title | Rating | Votes |
|---|---|---|---|
| 1 | The Arrival | 7.6 | 425 |
| 2 | The Wolf at the Door | 7.7 | 365 |
| 3 | Natural Order | 7.7 | 349 |
| 4 | Oil & Water | 7.8 | 358 |
| 5 | Primal Instincts | 7.5 | 346 |
| 6 | Distress Call | 7.7 | 333 |
| 7 | Entrapment | 7.8 | 325 |
| 8 | Leverage | 8.4 | 366 |
| 9 | No North Star | 7.6 | 305 |
| 10 | All In | 7.5 | 271 |
| 11 | Mixed Signals | 7.6 | 264 |
| 12 | Serenity | 7.6 | 260 |
| 13 | The Outpost | 7.5 | 257 |
| 14 | The Last Mermaid | 7.4 | 254 |
| 15 | Sacrifice | 7.6 | 259 |
| 16 | New World Order | 8.2 | 316 |
8.11 avg 10 episodes 7.9 → 8.5 42 min avg
| # | Title | Rating | Votes |
|---|---|---|---|
| 1 | Borders | 7.9 | 288 |
| 2 | Revelations | 8.0 | 258 |
| 3 | Survivor | 8.1 | 237 |
| 4 | Life and Death | 8.0 | 241 |
| 5 | Mommy and Me | 7.9 | 238 |
| 6 | The Island | 8.2 | 239 |
| 7 | Northern Exposure | 8.3 | 242 |
| 8 | 'Til Death Do Us Part | 7.9 | 226 |
| 9 | A Voice in the Dark | 8.3 | 245 |
| 10 | The Toll of the Sea | 8.5 | 330 |