Because the kaito service is limited and there's no overnight accomodation available on Po Toi, I've always tried to make sure to catch the second last kaito departing from the island (rather than the last kaito of the day because I worry about it getting too full). Nonetheless, each time that I've been on Po Toi, I've managed to venture onto "new" ground; with my going on its Rugged Trail (which I previously couldn't visually make out!) on my second visit, and "off trail" to the island's southern tip on my third visit... ;b