| Name | First Aired | Runtime | Image | |
|---|---|---|---|---|
| S04E01 | S.O.S. |
July 6, 2018
|
12 | |
| S04E02 | The Mermaid Cave |
July 13, 2018
|
13 | |
| S04E03 | Siren Song |
July 20, 2018
|
12 | |
| S04E04 | Whale Song |
July 27, 2018
|
12 | |
| S04E05 | The Octopus Mermaid |
August 3, 2018
|
13 | |
| S04E06 | The Mermaid Ghost |
August 17, 2018
|
12 | |
| S04E07 | The Final Lock |
August 24, 2018
|
13 | |
| S04E08 | Trapped |
September 1, 2018
|
12 | |
| S04E09 | The Storm |
September 8, 2018
|
13 | |
| S04E10 |
Atlantis
series finale
|
September 22, 2018
|
15 |
No artwork of this type.
No artwork of this type.
No artwork of this type.