Originally Posted by
LapLap
If we become aware of possibility of a ferry cancellation on our return and can't secure a place on a ferry leaving the day before, then it seems we can change the flights (outside of 24h deadline). But if the ferry cancellation only becomes apparent on the day of travel the not sure what we should do. JAL website doesn't go into what happens when travel is disrupted using award bookings made with non JAL FFPs.
Yes, Avios bookings cancelled before 24 hours from departure are refunded but you may pay a £35 per person redeposit fee, not exceeding whatever cash you actually spent at the time of booking. In the final 24 hours, Avios becomes completely inflexible and so you are at the mercy of whatever JAL would do during unrelated irrops. And I doubt very much that you can make advance assumptions about this. So you'd need a plan B and potentially insurance cover if the potential losses were beyond self-insurance. You could also make a second Avios redemption booking 36 hours after the first, so you would have an ability to cancel the fallback. Single redemptions would seem more flexible here rather than returns.