In the event of a landing being effected without their having been able to prevent it, and also if they saw that they were on the point of being cut off by the brig's boat, Ayrton and Pencroft were to return in their boat to the shore and proceed towards the threatened spot.
Ha azonban a gonosztevőknek mégiscsak sikerülne partra szállniok, vagy pedig valamelyik csónakjuk a briggről bekerítéssel fenyegetné a telepeseket, akkor Pencroff és Ayrton visszatér a pirogon a szigetszegélyre, és a leginkább veszélyeztetett pontra siet.