Is the Bristol Channel rough? What to expect on the crossing
Often at the western end, around Lundy, and much less in the inner channel. The channel opens to the North Atlantic, has a tidal range of 13 m, and Lundy is often windy. Wikipedia gives the Oldenburg's crossing to Lundy as about two hours on average, depending on ports, tides and weather.
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Channel · South-west England and Wales · Reputation among passengers: has a long-standing reputation for rough passages.
- Low
- Moderate
- High
- Very high
Roughness summarises typical reported conditions for this crossing, not a forecast for any given sailing.
Atlantic swell and a 13 m tidal range
In the Nausea Index table of the 128 sea crossings we cover, the Bristol Channel is rated rough, one of 38 in that band, with 6 rated higher. Full table: the roughest sea crossings, ranked.
Key facts
- The Bristol Channel is a channel, and passenger reports place it in the high roughness band.
- The mechanism behind that reputation: Atlantic swell and a 13 m tidal range.
- Conditions are reported roughest in January, February, March, November and December.
- The calmest months are usually April, May, June, July, August and September.
- It is also known as Môr Hafren.
Why is the Bristol Channel so rough?
The Bristol Channel runs from the Severn Estuary to the North Atlantic Ocean, and much of the coastline at its western end faces west towards the Atlantic. Lundy lies where the North Atlantic Ocean and the Bristol Channel meet, and it is often windy. The channel can be hazardous because of its strong tides, and the tidal range reaches 13 m. In modelled data the inner channel off Cardiff and Newport is far calmer, with daily peak wave heights averaging about 0.4 m, against about 2.0 m near Lundy.
When is the Bristol Channel roughest?
MS Oldenburg carries visitors to Lundy from April to October, and a helicopter serves the island from November to March. Modelled wave heights near Lundy are lowest from April to September and highest from November to March. Waverley visits the Bristol Channel on set dates in its season.
| Roughest water in Jan | Roughest water in Feb | Roughest water in Mar | Roughest water in Apr | Roughest water in May | Roughest water in Jun | Roughest water in Jul | Roughest water in Aug | Roughest water in Sep | Roughest water in Oct | Roughest water in Nov | Roughest water in Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Roughest | Roughest | Roughest | Calm | Calm | Calm | Calm | Calm | Calm | Mixed | Roughest | Roughest |
Typical seasonal pattern, not a forecast. Any month can deliver a calm crossing or a bad one. Check the marine forecast for your sailing date. Select a month to see every sea and ferry crossing ranked for it.
Month bands: Dizzout sea-state data for Bristol Channel, built from the reports and sources listed at the foot of this page. Free to cite with a link to this page.
Where to be on board
Front to back
- Bow (front)Avoid
- MidshipBest
- Stern (aft)OK
The crossing: About 2 hours
Roughest stretch: The open water around Lundy
Sit low and near the middle of the ship. The exposed part is the open water near Lundy, far from the mainland shelter.
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The crossings that cross it
| Route | Typical duration | What to know |
|---|---|---|
| Bideford to Lundy | About 2 hours on average | MS Oldenburg. The two hour figure is Wikipedia's average, and the time depends on ports, tides and weather. |
| Ilfracombe to Lundy | About 2 hours on average | MS Oldenburg. The two hour figure is Wikipedia's average, and the time depends on ports, tides and weather. |
| PS Waverley cruises from Bristol Channel ports | Day, afternoon and evening cruises | Waverley visits each area on set dates in its season. Departure points include Bideford Quay, Minehead Harbour and Penarth Pier. |
What helps on this crossing
- Sail in summer. MS Oldenburg runs from April to October, and modelled wave heights near Lundy are lowest from April to September.
- Sit low and near the middle of the boat and keep your eyes on the horizon. Wikipedia gives the Lundy crossing as about two hours on average.
- Check the day's sailing. Waverley says it emails and texts you if a sailing cannot operate, shows sailing updates on its website, and may skip a pier because of weather.
- Dizzout, a drug-free sound therapy app for passengers: it works with any headphones once nausea starts, with relief in about 90 seconds.
For the full toolkit see the seasickness guide, or what to do once it has already started. For what the trials actually say about the oldest trick on that list, see the verdict on looking at the horizon. If the rocking follows you ashore afterwards, that is land sickness, which is normal, and it passes.
Frequently asked questions
Is the Bristol Channel rough in July?
July is one of the calmest months in modelled data for the water near Lundy, where the daily peak wave height averages about 1.3 m. MS Oldenburg carries visitors in the summer months, April to October. The channel's strong tides still matter, and Wikipedia gives the Lundy crossing as about two hours depending on ports, tides and weather.
Is the Bristol Channel rough in January?
January is one of the roughest months in the same data, with the daily peak wave height near Lundy averaging about 2.6 m. Wikipedia says visitors reach Lundy by helicopter from Hartland Point in the winter months, November to March, and by MS Oldenburg from April to October.
Is the Lundy ferry rough?
It can be. Lundy lies where the North Atlantic Ocean and the Bristol Channel meet, and it is often windy. Wikipedia gives the crossing as about two hours on average, depending on ports, tides and weather. Waverley, which also sails in the channel, says sea conditions may make its ship roll or pitch.
Where is the Bristol Channel calmest?
In modelled data the inner channel off Cardiff and Newport is far calmer than the outer channel. The daily peak wave height averages about 0.4 m there, against about 2.0 m near Lundy. The tidal range still reaches 13 m.
Other crossings
Sources & further reading
- https://en.wikipedia.org/wiki/Bristol_Channel
- https://en.wikipedia.org/wiki/Lundy
- https://waverleyexcursions.co.uk/plan-your-cruise/departure-points/bristol-channel/
- https://waverleyexcursions.co.uk/plan-your-cruise/timetables/
- https://waverleyexcursions.co.uk/plan-your-cruise/useful-tips-and-safety-information/
- https://waverleyexcursions.co.uk/contact/faqs/
- https://open-meteo.com/en/docs/marine-weather-api
- https://marine-api.open-meteo.com/v1/marine?latitude=51.2&longitude=-4.67&start_date=2015-01-01&end_date=2024-12-31&daily=wave_height_max&models=era5_ocean&timezone=GMT
- https://marine-api.open-meteo.com/v1/marine?latitude=51.4&longitude=-3.3&start_date=2015-01-01&end_date=2024-12-31&daily=wave_height_max&models=era5_ocean&timezone=GMT
Sea conditions described here are typical patterns drawn from published marine and operator information as of July 2026, not a forecast: conditions on any given sailing depend on the weather that day, and any month can deliver a calm crossing or a bad one. Route and operator names are trademarks of their respective owners; Dizzout is not affiliated with or endorsed by them. Seasickness sensitivity varies from person to person; this page is informational and not medical advice.