ILCA 1 was on starboard tack and therefore had right‑of‑way under Rule 10.
ILCA 217956, approaching on port tack, was required to keep clear.
When ILCA 217956 began tacking, Rule 13 applied: she had to keep clear of other boats until she was on a close‑hauled course on starboard.
ILCA 217956 completed her tack close astern of ILCA 1 without contact.