[2] To the north, St Martin's is joined by a tidal causeway to White Island.

Despite its modernity, the daymark, alongside some prehistoric cairns, is a Scheduled Ancient Monument.

[5] St Martin's returns one councillor to the Council of the Isles of Scilly, the same as the other "off-island" wards.

Secondary pupils board at the St Mary's main campus,[6] staying there on weekdays and coming back and forth to their home islands on weekends.

[7] Students at the sixth-form college level reside and board elsewhere,[8] in mainland Great Britain.