The inside boat who tacked in
The situation
Short of the layline, Ella tacks from port to starboard inside the zone, ending up overlapped inside a boat that has been on starboard fetching the mark since before the zone. Ella calls for mark-room as the inside boat; the boats nearly touch and she protests.
Ella ends up overlapped on the inside at the mark, and the inside boat gets mark-room — so the outside boat should have given way.
The question
Ella is inside at the mark — doesn't that earn her the room?
The ruling
No — the obligation runs the other way and Ella is penalized. Because she passed head to wind from port to starboard in the zone, rule 18.3 switches rule 18.2 off between her and the starboard boat fetching the mark — her inside overlap earns her nothing. Instead she must not cause that boat to sail above close-hauled to avoid contact, and she must give it mark-room if it becomes overlapped inside her. On top of that, rule 13 applied while she tacked. The boat that tacks in gives room; she does not receive it.
Tack inside the zone and you owe room to the boat that was already fetching — never the reverse (rule 18.3).
Opens the situation on the boat-length grid — scrub it and see exactly how the boats meet. Free, no account needed.
Rules cited
See the underlying rule: Rule 18.3 — Tacking in the Zone.