- Actor Allusion: Eline Powell had played a siren in King Arthur: Legend of the Sword.
- California Doubling: Bristol Cove is said to be in Washington, but the show is filmed in Horseshoe Bay on the coast of British Columbia.
- Fake American:
- Alex Roe, who plays Ben, is originally from the UK.
- Fola Evans-Akingbola (Maddie) is likewise from the UK.
- Rena Owen (Helen Hawkins) is from New Zealand.
- Non-Singing Voice: Mariana Barretto provides the voice of the Siren Call.
- What Could Have Been:
- The title was originally going to be 'The Deep'.
- Early drafts had Ryn's name as Po.
Trivia / Siren (2018)