Did the Royal Navy consider replacing Sea Cat with Rapier?
Short answerThe answer is no: by the time Rapier had become satisfactory, Sea Wolf was already well underway and offered the better system.
NotesSeveral missile options were examined, but the answer does not identify Rapier as a replacement pursued by the Royal Navy. Rapier had issues that limited its appeal for the intended role. By the time it had matured, development of Sea Wolf was already well advanced. Sea Wolf is judged the better system in this comparison.