For a stay on Scilly, which transport might be the better option? The risk of motion sickness has us hesitating on taking the Scillonian. Not sure how often flights are cancelled or how flexible is booking (the day before or day of bookings).
Where are you coming from (I assume England since you posted under England)? I don't know what a Skybus is...you mean a plane? I'm not sure why you're worried about cancellations - is there any evidence of many cancellations? I wouldn't book a flight the same day or the day before because the fare will be higher and budget flights would be likely sold out. The earlier you book (using budget carriers at least), the better fare you get.