Fast route
Do this in order
- Step 1
Progress the mermaid and Luna Bay story until Mermaid form is granted.
- Step 2
Finish the form-unlock dialogue and any required water-area objective.
- Step 3
Transform into Mermaid form in a valid water location to confirm the unlock.
Prepare before you start
Unlock the required tool, form or region first. Carry food and leave inventory space so a successful catch or collectible is actually recorded.