Two islands in the far northeastern waters of Hong Kong were difficult to get to until recently. A weekend ferry service has now changed that.

This hike is mostly gentle and easy. Walking time: 3-4 hours of a full-day excursion.

Your ferry departs from a pier at Ma Liu Shui, which is 15 minutes’ walk from Exit B of University station on the East Rail. It only runs on Saturdays, Sundays and public holidays. It leaves at 9am, and it’s the only departure of the day, so arrive early if you can to make sure you get a seat. Turn right as you leave the subway under the Tolo Highway; tickets are sold from a makeshift desk under a sun shelter near the landing steps. The fare is HK$90 per person for the round trip. Call 2555 9269 for enquiries.

The boat sails the length of Tolo Harbour and then out through the narrow channel into the open sea of Mirs Bay, and a tour guide gives a running commentary on the islands, beaches and rock formations you pass along the way. (This area is part of the Hong Kong Unesco Geopark due to its unusual geology, and one of the islands you pass is where dinosaur fossils were recently found in Hong Kong for the first time). The guide gives a talk in Cantonese but will also answer any questions in English.

Passing between Double Island and Crescent Island, you sail through the protected waters of the Double Haven marine park before arriving at Kat O pier at about 10.45am. Stay on board, because the boat quickly departs again to make the short crossing to Ap Chau. Disembark here.

Also known as Robinson Island, Ap Chau is the smallest inhabited island in Hong Kong. There’s a tiny fishing village, and you walk through it to reach the island’s famous feature, a sea arch called the Duck’s Eye.

Ap Chau is made of an ochre-coloured sedimentary rock called breccia, and it is eroded by wave action to create a wonderland of shell-encrusted rock pools. Children will enjoy looking for crabs and shellfish. Looking west, the green coastline opposite is part of Hong Kong’s Plover Cove country park, but looking north, the built-up shore is part of Shenzhen in Guangdong province.

You have time to explore the rock pools – or make a clockwise circuit of the wave-cut platform that surrounds the little island – before coming back to the village. The Ap Chau Story Room in the former village school contains a historical exhibition. Hundreds of people once lived on the island but only a handful live here permanently now. You won’t find any temple on the island: unlike other fishing villages, where the deities Tin Hau and Hung Shing are usually worshipped, Ap Chau has long been a Christian community.

The ferry leaves again at 12.30. It crosses back over to Kat O, and this time you should alight. Kat O’s English name is Crooked Island, thanks to its strange shape: mountainous peninsulas extend east, southeast and southwest from the main village.

You can take any number of paths to explore, but one suggested route is this: turn right from the ferry pier, then left to follow the signs for Ko Pang Teng. Steps uphill lead you to a viewing point over the beautiful deserted beach of Tung O Wan, and then a further climb brings you to a spot overlooking the jungle-fringed bay of O Pui Tong. It’s a lovely sight.

Following the path downhill brings you to the sandy shore, and you can then bear right to walk south – maybe taking a detour to a picturesque abandoned village – until you loop back to the southern end of the harbour village.

Here is the colourfully painted house of Dominique Chan, an artist from France who has married a Kat O woman and now lives here. He is happy to show you his work. Next you come to the village’s renovated Tin Hau temple, and then you are back amid the old-style houses near the pier. Stalls sell locally made drinks, dumplings and red bean desserts, and an open-air restaurant under a banyan tree serves food.

The ferry departs at 3.30pm for your return journey to Ma Liu Shui. Don’t miss it, because there isn’t another one today!