Portmuck Harbour is situated on the northeast coast of Ireland to the east of Larne Lough and on the seaward side of the Islandmagee peninsula. Tucked into the peninsula, to the northwest end of the Isle of Muck, it offers a small harbour with an anchorage immediately offshore and the opportunity to dry out alongside its pier.

The little bay provides a tolerable anchorage with shelter and protection from southeast through south to west in winds up to 4 to 5. Although there are no off-lying dangers, and the bay can be accessed at all stages of the tide, attentive navigation is required for access. Rocks extending from the pierhead and the opposite shore require good visibility and keen observation whilst anchoring.

As Larne’s High-Speed Sea Services ferry lifts and drops off the plane a bow wash can roll a great distance into the bay. Boats at anchor here should be prepared for an occasional short sharp wave. The direction and velocity of the tide should be the central feature of any navigation planning in this area.

Keyfacts for Portmuck

Position and approaches

Haven position

54° 50.878' N, 005° 43.673' W

This is the position of Portmuck’s pierhead.

What is the initial fix?

This is located 400 metres north of the bay outside of Portmuck’s pier. A course of due south for 200 metres along Islandmagee shore leads into the anchoring area that is the small bay north of the car park.

What are the key points of the approach?

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How to get in?

Portmuck is a pretty harbour located on the northwest coastline of Islandmagee. It is situated close inside a small coastal islet, the ‘Isle of Muck’ situated 300 metres off the mainland, that is connected to the shore by a narrow drying ridge of stones and boulders. The small harbour fronted by a little bay has a drying pier and a boat slip.



A local hazard for vessels approaching from Larne or the north, and closely following the coastline, is the foul Skernaghan Point. Skernaghan Point is the northernmost point of Islandmagee and it should be given a berth of at least 500 metres to avoid a rocky outcrop that stretches northward from it.



On rounding Skernaghan Point, continue southeast alongside Islandmagee’s three miles of precipitous cliffs that range in height from 15 to 31 metres. This coastline is clear of obstructions and a distance of 150 metres from the rocks, or holding to the 10-metre contour or deeper, clears all dangers.

The 37 metre high Isle of Muck will be clearly seen on the bow all the way. The high and bare green island presents a perpendicular sea facing cliff to the east. It is attached to the shore by a narrow neck of shingle beach.


Local hazards for vessels approaching from the south are few. The southern extremity of the coast of Islandmagee lies five miles to the south of Muck Island. It is readily identified by Black Head lighthouse that is situated on the northern extremity of Belfast Lough.

Blackhead Lighthouse - Fl 3s 45m 27M position: 54° 46.016’N, 005° 41.338’W

To the north of Black Head, the coast of Islandmagee presents a steep perpendicular cliff composed of black basaltic rocks. At ‘The Gobbins’ this attains a height of 45 metres. Deepwater will be found close in under the cliffs with no outlying dangers.




The Isle of Muck situated close off the black basaltic cliffs of Islandmagee will be visible all the way on the bow from Black Head. The preferred approach is to round the island, keeping at least a 400 metres off the north most stacks of the island, and then to turn in towards the initial fix.




It is possible for shallow draft vessels to pass between the islet and Islandmagee shore at high water. The island is attached to the shore by a narrow neck of shingle beach that exposes at low water. However, this narrow connecting ridge can be covered by as much as two metres at high water springs. But this is not always the case and it can vary according to barometric pressure and wind direction. As such the cut between the islet and shore has many variables and the draft needs to be moderate or small. Hence the recommended approach is to round the island on the outside.


The Portmuck Initial Fix sets up a northern approach into the bay. Located 300 metres northwest of Portmuck’s pierhead, just inside the 4-metre contour, it takes a southern approaching vessel well clear of the exposed reef and hidden rocks that extend 150 metres northward from the harbour’s pierhead.

A course of due south for 200 metres along Islandmagee shore leads into the anchoring area.


Anchor in the small bay approximately 200 metres north of the car park with the slip open of the head of the pier. Good sand holding will be found here in 5 metres.

The small pier at Portmuck dries out entirely beyond the pierhead at low water springs. However, at High Water Springs, a vessel can find as much as 3.5 metres against the wall. Boats that can take-to-the-hard may dry out alongside on sand with some stones.



The harbour is entirely exposed to anything from the north. It is possible to achieve some measure of protection from these conditions by anchoring in 3.5 metres to the south of the drying ridge that connects the islet to Islandmagee. The northerly protection available here is limited and in such conditions, a vessel would be best advised to head south to Carrickfergus or the anchorages along the north shore of Belfast Lough.

Why visit here?

Portmuck derives its name from ‘Muck Isle’ or ‘Isle of Muck’ itself a direct translation from the Gaelic ‘Inis Muc’. 'Muc' means 'pig' in Irish and Inis means ‘islet’. It is believed the island acquired its name from its earlier inhabitants by appearing to resemble the shape of a sleeping pig.



The peninsula’s name, 'Islandmagee', on which the harbour is situated, hails from the Portmuck area. The name is directly derived from the Gaelic 'Oileán MhicAodha' meaning 'MacAodha's island'. The Gaelic MacAodha clan, who owned and controlled the peninsula, had their home at Portmuck. From their time right up to today the little bay of Portmuck has been adapted to play many roles through history.

It hosted at various times a monastery, fortress, revenue station, coast guard station and was well known for smuggling. The present harbour of Portmuck was specifically built to facilitate the industrial role of Islandmagee limestone for export. But this trade fell into terminal decline by the 1920’s and by the end of the decade the harbour went into ruins. In the 1980s government grants were made available to support local fishing activity from small locations such as this. If a number of fishermen were dependent on a pier in question, central government funds would be made available for renovation. As such restoration work took place at Portmuck creating the beautiful small harbour that exists there today. It is often said that a number of deceased fishermen supported the locals in their application.

Today the now partly silted pier is the focus of leisure pursuits for the community and beyond, with a picnic area and cliff top walks offering views across the Irish Sea out to Scotland. The strip of coast, for a mile or so either side of the harbour, was acquired by The National Trust in 2003. It was designated an ‘Area of Special Scientific Interest’ (ASSI) for its beauty and the variety of wildlife it hosted. The National Trust set in place a northern and southern linear trail to enable visitors to engage and enjoy the dramatic views and coastal scenery over the Isle of Muck from Islandmagee. The terrain for both paths is mostly grassy with occasional uneven rocky surfaces, steps, swing gates and stiles throughout the walks.

The northern route is accessed from the car park across the picnic area; go through the wooden swing gate, turn left and follow the path up the slope to the cliff top. The National Trust walk is bounded by private land that is clearly marked, so return by the same route. This path offers a particularly attractive opportunity to photograph a vessel at anchor in the bay. Here the cliff provides an elevation of almost 40 metres. With Muck Island situated in the backdrop and the Irish Sea out beyond, it makes for a spectacular photo opportunity of a vessel at anchor.

The southern route may be accessed by ascending the steps beside the harbour. Follow the path to the rocky shore and continue to where the low water ridge over to the Isle of Muck exposes itself, then follow the trail up the slope to the right. Then follow the main grassy path for about a half mile to the end. Return by retracing your steps or take another trail that leads to a minor road that leads back to the harbour car park. This route provides spectacular views of Muck Island from the adjacent shoreline and the cliffs above it from the south.

Muck Island, despite its name, is technically not an island. Although located 300 metres off the mainland an ever-shifting ridge maintains a connection to Islandmagee. This dries at low water springs and is scarcely covered at neaps making it possible to walk out to the island over a mixed sand and shingle bar. At high water springs, however, it has up to two metres of cover. The island itself lies north to south and has an overall length of about 1,000 metres, and has three small rocky stacks off the northern end. Its height increases west to east presenting attractive steep 30-metre high basalt sea cliffs to seaward.

The combination of the east facing cliffs and coastal grasses in the central part the island provide an attractive mixture of wilderness habitats to a wide variety of seabirds. It is now a nature reserve and is the home of Northern Ireland’s second largest cliff-nesting seabird colonies. Kittiwake, Razorbill, Black Guillemot and Guillemot all breed here. It is looked after by the Ulster Wildlife Trust and although passable on foot, for a short period around low water springs, the island is a bird sanctuary with no unauthorised public access. The National Trust who actively promote the coastal paths and have positioned mainland information signs that actively discourage visitors crossing to the Island.

From a coastal cruising point of view, Portmuck is the hidden gem that is too often overlooked along this coast. It offers an excellent stop-off point for northbound or southbound vessels making their way along the coast. It also provides an ideal point of departure or arrival for the Western Isles of Scotland. It is non-tidal, free from off-lying dangers and access is immediate and straightforward from seaward. It also serves as a highly convenient tide wait location to allow mariners to take full advantage of favourable tidal streams that are the dominant feature of this area of the coast, not to mention it its highly useful half-tide eddy to the north of the island. Those who drop in here will be treated to a stunning little harbour that provides access to a beautiful coastline within a few strides out from the pierhead.

What facilities are available?

Toilet blocks are available on the pier and the harbour has a good slip. Contact the harbour master, who could not be more helpful, for any resources required including basic Marine engineering that may be available locally.

The small village of Mullaghboy, one mile away, has basic provisions to service its population of about 300 people and a café that serves good food. Almost everything else is available at nearby Larne harbour.

Any security concerns?

Never a problem known to have occurred in Portmuck Harbour.

With thanks to:

Terence Stitt, Portmuck Harbour Master. Photography with thanks to KyleH, Wilson Adams, Albert Bridge, Mary and Angus Hogg, Eskling, Aubrey Dale and Mike Simms.