This is the longest of the walks on my website, but it is also one of my favourites, and one that is constantly changing with the tide, the season and the time of day.

Because most of the land is MOD owned (you have to check in and out at very imposing-looking gates to access the path) it is completely undeveloped, making it a real haven for wildlife and birds - so don't forget your binoculars!

Distance: 13 km, 8.1 miles

Walking Time: 3 hour 30 mins

Difficulty: Easy

Wheelchair Accessible: No

Start/End: The Lord Raglan pub in Queen Street, Emsworth

Access:
3 minutes walk from the Square in Emsworth

Itinerary

This walk starts from St Peter’s Square, where there is convenient parking (paid) in South Street as well as the bus stop for the 700 Coastliner bus.

From the square, walk east along High Street, and then turn left down Queen Street until you reach the Old Flour Mill on the left.

On your right, take the signed footpath between the houses, under the arch and through a gate onto the path between Slipper Mill Pond and Dolphin Quay.

The Slipper Mill was a tidal mill driven by the water held in the millponds as it drained out as the tide ebbs. The river Ems also feeds into the northern end of Slipper millpond making it brackish water. The mill here was first built in the 1760s, and was the first tidal mill in Emsworth. The last Slipper Mill closed in 1936 and was later converted into houses.

At the end of this path, go through the gate and then turn right past the converted mill and into the Emsworth Marina.

Walk through the marina passing the workshops and then bearing left through the boat storage yard. Turn left into the marina approach road, leaving the marina car park to your left.

At the end of the approach road turn right and walk south along Thorney Road. Take the first road on the left into Thornham Lane and follow this road straight until you reach Thornham Marina on your left.

You cannot walk through Thornham Marina so continue straight past some houses and then take the footpath to the left by some large rocks.

Continue straight on this path and at the foreshore turn right crossing a wooden foot bridge.

Keep going on the foreshore path bearing left and heading south until you come to a military security gate.

At the gate press the buzzer. You will be asked your details and contact telephone number. This is a formality as the land beyond the gate is Ministry of Defence.

This coastal path around Thorney Island is the start of the Sussex Border Path, a 150 mile long path, starting here and ending in Rye in the east (Click here for details).

After passing through the security gate, continue on the signed footpath south. Please note that you must not stray from this marked path into the MOD land, or you may find a troop of soldiers on your tail.

The MOD installation on Thorney Island dates back to 1938 when the RAF built the airfield as a key defence base during the Second World War. The RAF left in 1976 and today it houses Baker Army Barracks.

After about a mile you will pass a dinghy park. Just beyond, the path climbs up the bank towards the 12th century church of St Nicholas.

The church is worth a visit as you pass by. There is a commonwealth cemetery in the churchyard and has views over Bosham to the Chichester Cathedral. There are some benches in the churchyard for a break.

If the tide is low you can continue along the foreshore in front of the Thorney Island Sailing Club (TISC). If the path is flooded at high water, turn right before the club building, then left around the car park, keeping to the path to the other end of the club. The path turns left and then returns to the foreshore heading south.

At the tip of the island you will pass the sandy beach and dunes of Pilsey Island. This area is leased by the RSPB and is important for nesting and roosting birds. There is no public access from the footpath but there is a bird hide along the path, so we hope you remembered your binoculars!

Chichester Harbour is an Area of Outstanding Natural Beauty (ANOB) and used by around 55,000 birds who come here for the tranquillity and food-packed harbour mud. The majority of these visit in the winter months including over 10,000 Brent Geese.

Continue along the path as it turns west along the southern foreshore of the island.

You will pass on your left the remains of the landing lights for the approach to the airfield runway, and this stretch of water, know locally as Runway Bay, is a favoured location for harbour seals, either swimming close to the shore or basking on the mudflats at low water.

Looking to the south, you can see the sand dunes of East Head and the harbour entrance over towards Hayling Island, and between them the notorious Winner Bank – a very hard and shallow bank that can catch out the unwary boater.

During the summer months this is a very busy waterway from the Solent up to the marinas close to Chichester

Round the south west corner of the island is Marker Point, which is located at the southern end of Emsworth Channel and is marked by a green lit navigation mark.

Keep heading north following the foreshore path, looking across the channel to the eastern side of Hayling Island.

From here you can see across to Hayling Island, and as you move north, you can see across to the Hayling Bridge, Langstone Harbour and Portsea Island beyond.

At the security gate you may be asked your name again and then let through. Here you can either continue along the shoreline path or drop down the bank and walk along a wide track.

Looking to your right just after the security gate you look down Great Deep, which is the stretch of water that defines Thorney Island as an island. This again is a habitat rich in different types of birds.

At the end of either path, you pass in front of the ‘stilt’ houses and then turn right and walk through the marina.

The marina represents the remnants of the past history of Emsworth in terms of its ship building and oyster growing industries.

The first line of mooring pontoons on your left used to be a mast pond, where trees that were to be used for the ships’ spars were left in the sea water to mature and harden before being shaped into masts and spars.

The second pool on your left, and the main part of the marina, used to be another millpond feeding the Slipper Mill.

Walk straight through the marina and back out of the entrance that you originally entered through, and walk north straight on up Slipper Road.

At the end, next to the road bridge, turn left and walk back up Queen Street, right into High Street and back into St Peter’s Square.