Big Welsh Swim in Llyn Padarn, Llanberis, Snowdonia, North Wales

The BIG Welsh Swim, North Wales, UK

Saturday 11th July 2020

All aboard the swim train!

Catch the narrow gauge train to the end of Llyn Padarn to start your swim for a truly unique experience! With the spectacular backdrop of the Snowdon mountain range, the historic Dolbadarn Castle and Welsh slate quarries you can choose to swim the length of the lake, either once, twice or three times! We have a mid length option too!


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The Course

The BIG Welsh Swim will take place in Llyn Padarn, Padarn Country Park, Llanberis, Snowdonia National Park, North Wales. The swim route will involve lengths of the lake (each length is 3km) with a choice of 4 different distances to choose from. Wetsuit and non-wetsuit places are available! The lake is surrounded by some of Snowdonia’s most stunning scenery including beautiful woodland, a historic castle, the old slate quarries that tower above the valley and the small narrow gauge railway that we’ll use to transport you to the end of the lake!

location: Gilfach Ddu station, Llyn Padarn Railway, Llanberis, North Wales. LL55 4TY.


  • Mid way: 1.3km
  • One way: 3km
  • Two Way: 6km (you will not take the train on the 2 way swim)
  • Three way: 9km

Aid stations: 3 stations over each length of the lake: both ends and half way point.

Cut off time: 4.5 hours from start time for each distance. The race organisers and appointed staff can retire a participant at any time if they judge them not capable of finishing due to fatigue or poor physical condition. You may be prevented from starting your final length if it is deemed you will not complete it by the cut off time.


Online entry opens: 6th September 2019.

Online entry closes: 4th July 2020. (No entry changes or transfers can be made after this time)

You must be over 18 years of age on the day of the race to enter the event. 16+ participants will need parental consent to take part in full length swims. Age 8 and above can complete the 1.3km swim if accompanied in the water by a fee paying adult who will take complete responsibility for them.

Entries will be opened in 3 staggered waves for 2020 and there will be no waiting list available. Please read our terms and conditions (updated for 2020) carefully before entering.

Entry prices

  • Mid way: £48 / Junior (age 15 & under): £30
  • One way: £54
  • Two Way: £59 (no train ride included)
  • Three way: £70

Entry fee includes:

  • Full water safety cover
  • Train ticket (excluding 2 way entries)
  • Event swim hat
  • Event timing
  • Fuel and hydration during event
  • Race medal
  • Free event photos
  • Prize for winners in each distance category – supplied by Zone3


Mandatory equipment for wetsuit competitors

  • Swim hats supplied by event organisers must be worn at all times when in the water
  • Neoprene Wetsuit
  • Goggles
  • Tow floats may be used but are not mandatory for wetsuit wearing participants

Mandatory equipment for non-wetsuit competitors

  • Swim hats supplied by event organisers must be worn at all times when in the water
  • Suitable swimwear (shorts style suits and rash vests are acceptable. No neoprene other than that listed below)
  • Goggles
  • 1 Tow float (must be a dedicated swimming tow float)

Additional equipment that may be used: Neoprene socks and non-webbed neoprene gloves, neoprene hat (worn under event swim cap), ear plugs

Additional equipment that may NOT be used: Snorkles, flippers, hand paddles, webbed gloves, headphones, pull buoy, buoyancy shorts or other floation aids, any power assisted aids.


Registration will take place: Lake side, Gilfach Ddu, Llyn Padarn Railway, Llanberis, North Wales, LL55 4TY.
You will be issued with your event hat and timing chip. Please arrive as early as possible and take note of the parking arrangements as there may be a short walk! There will be Friday evening and Saturday morning registration. Times will be confirmed in the event handbook which will be available one month before the event date.


The compulsory briefing will be held on Saturday 11th July 2020 at Lake side, Gilfach Ddu. 3 way and half way swimmers will board train 1 which will leave promptly at 9.00am so need to be ready to leave straight after the briefing. 3km swimmers will board train 2 which will leave promptly at 10.00am. If you miss the train you will need to make your own way to the other end of the lake. Participants doing a two way swim do not need to catch the train.

Bag drop

There will be a place for 6km swimmers to leave shoes/ 1 SMALL bag close to the swim start. 1.5km, 3km & 9km swimmers may take shoes/1 SMALL bag with them on the train and this will be transported back to the finish line to be picked up at the end of your swim. Please only leave essential items and do not place fragile or valuable items in the bag drop as we cannot take repsonsibility for them.

Provisional schedule of events

Saturday 11th July 2020 (Times will be confirmed in the event handbook which will be available one month before the event date.) 

07:00  Registration opens
08:30  Registration closes
08.40  Route and safety brief
09:00  Train for Mid way and Three way swimmers departs
09.20 Race start – Two way swimmers
09.20 Race start – Mid way swimmers
09.40  Race start – Three way swimmers
10:00  Train for One way swimmers departs
  Race start – One way swimmers
13:00  Prize giving

Entries are open!

Entries this year will be opened in three waves: 60% will be released on 6th Sept 2019, a further 30% on 1 Feb 2020 and 10% on 1st May. There will be NO waiting list. 

Race rules & Terms & Conditions

Please read the updated 2020 race rules and terms and conditions of entry throughly before signing up. You can read them in full here.  Please be aware that we offer a no refunds policy and limited entry deferral options (up to 6 weeks before the event). You are permitted to transfer your entry into another name up to 1 week before the event date. Please only enter this event if you are happy with these terms. Please see our FAQ page for more information. We recommend you take out individual sports event insurance to cover any losses due to unexpected circumstances that prevent you from taking part.

Event Handbook

An updated final version will be available on the competitors page (a link is in your entry confirmation email from SiEntries) a few weeks before the event. Please read all the information throughly to get the best out of the day!

Water temperature

Going on average water temperatures for  July over the last few years, we expect the water temperature in Llyn Padarn to be between 16°C and 18°C for the Big Welsh swim event. The temperature in the lake can vary quite a lot depending on the amount of rainfall and sunshine we have but we will keep you updated on the water temperature in the run up to the event.

Event merchandise

The Big Welsh Swim 2020 commemorative t-shirts will be available for pre-order (to pick up on the day of the event). These are designed, produced and sold by an independent t-shirt designer. They are £15 each and are etchically produced from organic cotton! They are hand printed locally using environmentally friendly inks. You will be emailed approx 1 month before the event with the design and details of how to order one.

Love SwimRun and The Big Welsh Swim everyday vinyl printed logo t-shirts and hoodies are available for mail order in the Love SwimRun shop. Males sizes seem accurate. Female sizes come up small, so if you like a fitted look order your normal size or if you like a slightly looser fit go for a size up (eg for size 10: Small = fitted, Medium = looser fit).

Big welsh swim tshirt and hoodie

Official nutrition partner

Wild Trail will be helping to fuel you on our events this year as our official nutrition partner! Their all natural fruit and nut bars are made with just 5 simple ingredients you’ll know and love, see them at They are gluten free, dairy free, have no added sugar, are high in fibre and suitable for vegetarians and vegans! Best of all, Wild Trail bars are inspired by Snowdonia and are made locally in Wales.

Wild Trail Ad for website

Event Sponsor

We are super exited to have Zone3 on board as our Big Welsh Swim event sponsors. They will be suppling the winners of each category with a prize. Zone3 are also offering all Love SwimRun participants a 25% discount on their range of swimming gear and wetsuits! You will receive a special discount code once you have registered.

zone3 wetsuit discount

Charity partner

Love SwimRun are supporting Level Water during this event. We all know how wonderful swimming is! Level Water provides free one-to-one swimming lessons for children with disabilities.  Without these lessons, most of these children will never learn to swim. They provide lessons until children can swim 15m frontcrawl and backstroke.  From this point, these children are safe and independent in the water.  They can join group swimming lessons and even their local competitive swimming club!  The swimming lessons also help children with physical or sensory disabilities to develop confidence, self-esteem and resilience.  If we can give a child physical, social and emotional confidence through sport, we can change their trajectory in life.

Please help support Level Water by making a voluntary donation when you enter The Big Welsh Swim. Thank you!

Prizes & food!

Hot drinks, snacks and delicious hot food will be available to buy when you finish your race. All competitors will receive a Big Welsh Swim souvenir and a Wild Trail bar at the finish line. Prizes from Zone3 and Love SwimRun will be awarded to the first 3 male and female swimmers in each wetsuit distance category, and first three swimmers in the non-wetsuit category. Prizes must be collected on the day and no cash alternative to the prizes will be offered.

Parking & toilet facilities

There is plenty of public parking available near the event base (pay and display). Disabled parking is available there too. Please do not park on the road or cause any obstructions to access or gate ways. There are public toilets in the middle of the main car park, including disabled toilet. There changing areas but there are no shower facilities.


By car: Llanberis typically is 5 hours from London by car, 2 hours from Manchester. To access Llanberis turn off at Junction 20 of the M6 onto the M56, follow signs for NORTH WALES to reach the A55. Use post code LL55 4TY in your Sat Nav and follow signs for the Slate Museum. Public transport: The closest train station to Llanberis is in Bangor. Buses run from Bangor to Llanberis.


See our list of local accommodation providers here.

Spectator info

Spectators are welcome to come and support you at The BIG Welsh Swim! There are plenty of good spots from which to support your friends. There is disabled access to the registration/finish area though this is on a rough track, not tarmac. Dogs are welcome on leads.

Why not catch the train yourself? The first public train will run at 11.45. There will not be places available on the participants swim train for friends/family members I am afraid. If you take any photos or videos we would love to see them! If you are interested in marshalling on the day, please get in touch!