An elliptical cast — also called a Belgian or oval cast — is a continuous tension cast: the back cast is made in a relatively horizontal rod plane and then, without stopping, the forward cast is made in a more vertical plane. That separation of planes gives the back loop an oval shape, and there is no pause between the two strokes.

Use it when:

• The back cast ticks. An elliptical delivery makes ticking easier to prevent.
• You are casting large or heavy flies, sink tips and other complicated payloads — the guide calls it quite useful for these.
• The wind blows onto your casting arm side — it is one of the safe methods taught in the wind task.
• You want slack — it can set up a pile cast delivery.

Keep continuous tension throughout; a pause turns it into two ordinary casts.

Source

From the CI Study Guide (2025) (PDF), Task 5 — slack line presentation and the wind task (Task 22); defined in the FFI Fly Casting Definitions (Oval / Belgian / Elliptical Cast).