West coast Anglesey Ebb
Holyhead to South Stack: the best sea kayak launch in Wales and the cliffs behind it
Holyhead New Harbour is an all-tide, no-surf, fully sheltered launch, which is rare enough in Britain to make this coast worth the trip on its own. Seven miles southwest of it are the South Stack cliffs: 60 m of Precambrian rock, one of the largest seabird colonies in Wales, and a lighthouse built in 1809 at the foot of a 400-step staircase.
- Distance
- 7.2 nm
- Tide window
- 4.4-6.2 m springs, 2.3-3.2 m neaps
- Wind limit
- 10 kt
- Grade
- Intermediate
- Published
- 21 Aug 2026
Holyhead Mountain and the old rock
The cliffs at South Stack are made of some of the oldest rock in Britain: Precambrian schist and quartzite, around 600 million years old, standing as an island massif that was never covered by the younger sedimentary rocks of the rest of Anglesey. Holyhead Mountain behind it is the highest point on the island at 220 m.
For a paddler this geology matters because it produces vertical, clean rock with deep water at the base over a long stretch, which means there is no shoal to break the swell and no beach to land on. The section from North Stack to South Stack is 2 nm of sheer cliff with very few landing places, and it is the most exposed part of the day.
The overfalls and the passage
South Stack sits about 30 m offshore, separated from the mainland by a narrow channel that carries the whole of the ebb. On a 6.2 m spring the stream reaches 2.5 to 3 knots in the passage and forms overfalls on the southwest side of the stack that are visible for a mile.
The passage between the stack and the island is canoeable, but only near slack. At any other state it is a 3-knot stream through a gap 40 m wide with a rock wall on both sides; the correct decision for most groups is to go outside the stack, 300 m offshore, where the water is more predictable even if it is bigger.
Birds, and the season
The cliffs hold around 10,000 breeding seabirds: guillemot, razorbill, kittiwake and a small puffin population. The RSPB reserves the cliffs and the Ellin's Tower visitor centre on the headland above gives a view straight down onto the ledges. Landing on the cliffs is not permitted and there is nowhere to land anyway.
Chough are the local speciality: a red-billed, red-legged crow that nests in sea caves and on the cliff ledges, and is restricted in Britain to the west coasts of Wales, Scotland and Ireland. They are usually seen in pairs, flying with a distinctive flicking wingbeat, and they are one of the few birds a kayaker can identify from a mile away.
Making the round trip work
The clean plan is to launch at Holyhead New Harbour two hours before high water, paddle southwest along the coast past North Stack and the cliffs, round South Stack at slack, and come back northeast on the first of the flood. That gives a favourable stream on both legs and puts the exposed cliff section in the middle of the day when the wind is usually lightest.
The wind limit here is lower than the distance suggests. Holyhead is fully exposed to the southwest, and a force 4 to 5 with any west in it produces wind against tide at South Stack that makes the passage genuinely dangerous rather than merely difficult. Above force 4, the sensible alternative is Trearddur Bay and the sheltered inner coast, which is a much shorter and much less interesting paddle, but it is the right one.
Plan table
Before departure
- 01
Check the Irish Sea forecast for wind direction, not just speed
Any wind with west in it above force 4 produces wind against tide at the stack.
- 02
Time the South Stack passage at slack
The gap is 40 m wide with 3 kt of stream and rock on both sides at any other state.
- 03
Check the RSPB reserve rules
The cliffs are a reserve and landing is not permitted, nor is there anywhere to land.
- 04
Confirm the Holyhead harbour access
The new harbour slipway is all-tide; the old harbour dries and has a sill.
En route
- 01
Pass South Stack on the outside, 300 m offshore
The water is bigger but far more predictable than the inner passage.
- 02
Keep the group tight along the North Stack cliff section
There is no landing for 2 nm and no shelter in a southwest wind.
- 03
Watch for the Holyhead to Dublin ferry
It leaves the harbour at speed and the route crosses its track.
- 04
Turn for home on the first of the flood
The ebb runs 3 kt southwest and the return against it doubles the day.
Key numbers
- 7.2 nm round trip, 3 to 4 hours including the cliff section.
- Spring stream 2 to 3 kt past South Stack; the inner passage only at slack.
- Wind limit 10 kt, and 4 to 5 kt is the realistic ceiling in settled weather.
- No landing for 2 nm along the North Stack cliffs.
- Holyhead New Harbour is an all-tide, no-surf launch, which is why this coast is worth the trip.
Bail-outs
- B1 Porth Dafarch, 1.5 nm southeast, a sandy cove inside the bay
- B2 Trearddur Bay, 2 nm east, a lifeguarded beach in summer
Return leg：Return northeast on the last of the ebb or the first of the flood, keeping outside the South Stack overfalls. Holyhead Bay gives shelter on the way back into the harbour.