Rosmoney is located in Clew Bay, a natural deep ocean bay on the west coast of Ireland that is remarkable for the number of small islets that occupy its eastern portion. Rosmoney is the base for the Mayo Sailing Club offering an anchorage, club moorings, a pier and a club jetty for the convenience of landing.

Nested in the centre of the archipelago of islands the anchorage provides complete protection from all quarters if little in the way of air cover. Attentive navigation in daylight is required, and intricate channels must be followed between numerous drumlins within the archipelago which can be confusing.

Keyfacts for Rosmoney (Collan More Harbour)

Position and approaches

Haven position

53° 49.700' N, 009° 37.364' W

Collan More Bay to the north of Rosmoney Peninsula.

What is the initial fix?

This is the well-established entrance into Clew Bay setting up an approach between Inishgort Light House, Fl.10s11m10M, and the Dorinish Buoy, Fl.G. This is established approach through the drumlins to access the number of small islets that occupy the east and southeastern portion of the bay including Rosmoney and Westport.

What are the key points of the approach?

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What's the story here?

Clew Bay is a spacious inlet, with moderate depths of water and ease of access. It is remarkable for the number of small islets that occupy its eastern portion of the bay, many of which provide well-sheltered anchorages for leisure vessels. These remote anchorages are entered via intricate channels of which some lead to the commercial towns of Westport and Newport. The central Rosmoney, or Collan More Harbour, to the east of Collan More island provides all-round shelter and direct access to the mainland close to the bustling town of Westport.




The harbour has depths of up to 3.2 metres and ample water in the approaches save for the final pass into Collan More Harbour that has 1.7 metres CD. Home to a sailing school and a club the natural harbour has four visitor moorings available (as of 2018) amongst the ample club moorings. A new pontoon facility, located about 30 metres from the edge of the drying permanent pier, provides for convenient and safe landings.

How to get in?

Offshore details are available in western Ireland’s coastal overview for Slyne Head to Erris Head . The approach to the bay is well marked by Clare Island lying in the middle of the entrance, with Achill Island on its north side and the 756 metres high Croagh Patrick Mountain in the distance on the south shore. Clew Bay is then entered between Roonah Head and Achillbeg Island, about 5.7 miles north by northwest. Inishgort Lighthouse, to the north of the pass into the islands, is clearly visible throughout Clew Bay.

Inishgort - Lighthouse Fl 10s 10M position: 53° 49. 603’N, 009° 40.264’W



From the initial fix pass close to the Dorinish buoy Fl.G. and south of Inishgort lighthouse. When Inishgort lighthouse comes abeam steer for the 48-metre high summit of Collan More Hill 1⅓ miles east by northeast. This will lead about midway between 21-metre high Collan Beg Islet, to the north, and the 27-metre high Inishlyre Islet, to the south.

The path then bends southeastward to pass between Collan More Island, to the northeast, and Inishlyre, 600 metres to the south to pass over Inishlyre Harbour, immediately east of Inishlyre. Stay about 150 metres off the south coast of Collan More Island keeping an astern alignment of Inishgort Lighthouse in line with the northmost point of Inishlyre Island. When the water deepens to 8 metres or more you have arrived in the Sruhnameel Channel.

This channel passes between the southeast end of Collan More Island and Rosmoney Point opposite, the northern extremity of Rosmoney Hill. The pass is 200 metres wide but the drying shores of the islands on either side encroach upon the channel reducing the navigable entrance to a with of about 45 metres with 1.7 metres of water. Favour the Collan More Island side of a centre channel approach when entering Collan More Harbour. Keep off the shore to the north of Rosmoney Shore east of the point as it drys out to 60 metres and is shallow beyond. A rock, marked by a starboard-hand buoy that dries to 0.1 metres, extends out twice this distance 200 metres east of the entrance and is very much in the way of vessels making towards the jetty and pier.



Anchor in a depths of up to 3.2 metres with excellent mud holding north of Rosmoney Point. Land at the 30 x 5 metres piled pontoon on the south side of the harbour or by the drying pier 30 metres beyond near Mayo Sailing Club.

Mayo Sailing Club uses its own anemometer in Clew Bay , a useful resource for locals & visitors.

Why visit here?

Clew Bay, in Irish Cuan Mó, overlooked by Croagh Patrick to the south and the Nephin Range of mountains of North Mayo, is one of the most spectacular bays in Ireland.



Clew Bay's archipelago of small islands is a vast collection of drowned drumlins. A drumlin, derived from the Gaelic word droimnín, meaning a little hill ridge, is a long whale-shaped hill formed by glacial action. Drumlins may be more than 45 metres high and more than 0.8 km long and are often in drumlin fields of similarly shaped and sized hills. Clew Bays' drumlins were made 12,000 years ago when it was covered in ice. As the temperature rose and the ice retreated wave-like patterns of long oval mounds of boulder clay were deposited. Many of the hills on land around the bay are similar drumlins. They are part of a strip of rounded glacial hills which runs right across the country from Clew Bay to Strangford Lough in County Down.

But being open to the sea the Clew Bay drumlins are eroding away leaving them sloping from west to east with massive seaward facing boulder clay cliffs. Local lore suggests that there is one island for each day of the year. According to legend, Clew Bay gave West Mayo its ancient name of ‘Umhall’. This name is believed to have come from the translation of the Irish word for apples, ubhall or ull and it is thought the island swarm, which look like apples floating in the water, could have given rise to this connection.


It isn’t hard to be inspired by Clew Bay. It is one of nature’s great spectacles and a climb to the summit of Croagh Patrick will provide the perfect vista. The mountain is Ireland's famous ‘Holy Mountain', also known as “The Reek”, and the author William Makepeace Thackeray wrote of the 19th-century vista he took in from there “…the bay and the Reek, which sweeps down to the sea, and a hundred isles in it were dressed up in gold and purple and crimson, with the whole cloudy west in a flame. Wonderful, wonderful!”. Little has changed since and the swarm of drumlins is unlike anything else in western Europe.




It is this amazing spectacle that brought John Lennon to Dorinish Island, the twin green mounds linked by a natural causeway passed to starboard on entry, in order to retreat from a maddening world. He bought the island in 1967 and got planning permission to build a house on it. As it happens he never got as far as building upon the island having instead floated out, on a purpose-built raft, a wooden 'gypsy caravan' painted in psychedelic colours as a temporary home. But at the height of Beatlemania, Lennon wasn't ready to settle at that time and so he returned to England and the USA, but offered the use of it to Sid Rawle in 1970.

Known in Carnaby Street as the “King of the Hippies”, to establish his utopian vision of a commune on the island. The band of 30 hippies hacked it out on the island longer than most would have, but in 1972 the community finally disbanded after strong winds helped a dropped oil lamp to destroy their tents. Later Lennon told the New York Times he planned to retire to Dorninish and had even restarted plans to build on the island when he was killed in 1980. Yoko Ono said that Dornish was "a place where we thought we could escape the pressures and spend some undisturbed time together”. Four years later Yoko Ono sold the island, donating the sale price to an Irish orphanage.

Today Rosmoney is home to the Mayo Sailing Club which was established in 1976 to promote sailing in Clew Bay. There have currently more than 250 members taking part in various water activities during the season. The bay was also home to Glenans Sailing School which is no longer sadly.


From a sailing point if view Clew Bay, thickly studded with islands and surrounded with mountains, is one of the most magnificent of the great inlets on the west coast of Ireland. The complex drumlin coastline with its countless anchorages is perfectly explored by boat and nowhere is more central, convenient or scenic as Rosmoney. The boat can be safely left for visits to Westport which is a taxi ride away.

What facilities are available?

Water is available at the pontoon. Westport is less than 10km via a taxi (€15.00) and the large town offers a good opportunity to restock. Facilities in the town are good with a wide variety of shops including a supermarket, laundrette, internet cafe, doctors and chemists, banks and post office, fuel and gas from filling stations, and reputedly a chandlery +353 98 28800.

The town is the terminus of the 250 km Dublin-Westport/Galway railway line from Dublin Heuston in Dublin. This is complemented by a wide range of bus connections.

With thanks to:

PETER CRAVEN