ESSENTIAL EVENT INFORMATION 2025
SEA TO SUMMIT: YR WYDDFA
ARE YOU READY TO TAKE ON SEA TO SUMMIT:YR WYDDFA?
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This is our Essential Event Information document, which contains a comprehensive round up of everything you need to know ahead of topping out at the highest trig point in Wales! Soon you'll be stood on our coastal start line at Caernarfon Castle gearing up for an 'ultra' 29 mile day out bagging this famous and glorious peak! So, read on to find the answers to all your questions ahead of the adventure!
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Due to the scale and nature of Rat Race Events, changes to the course, structure and timings sometimes need to be made right up to the date of the event. To ensure you have the latest information and are fully prepared for the challenge that lies ahead, please check back on this EEI before travelling to the event.
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This EEI was last updated on: 17/09/2025 (Reminder: You MUST bring your running backpack to Tracker Collection so your tracker can be taped on when allocated)
IMPORTANT REMINDERS
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Online Disclaimer MUST be completed before Registration, you can do this HERE. You will be required to show your disclaimer completion confirmation email at the entrance of Registration before progressing to kit check and tracker collection.
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Tracker Collection is on Friday 26th September 1500 - 2100 outside the Harbour Office, Slate Quay, Caernarfon LL55 2PB . You must collect your tracker on 26th between these times. You MUST bring your running backpack to Tracker Collection so your tracker can be taped on when allocated.
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The start is at Caernarfon Castle, LL55 2AY.
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Bib Numbers will be posted out in advance of the event. You should expect to receive your adventure pack around 1-2 weeks before the event. International participants will be required to collect their adventure pack from the Help Desk at Tracker Collection.
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There will be a mass start at 06:45. Please aim to be at Caernarfon Castle at 06:15 so you can be relaxed and ready for the start. NB: This is no longer a waved start.
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Trilogy Medal: If you have taken on the trilogy over 2024/25 and this is your final of the three events, please complete the form HERE so we can confirm your eligibility and have your shiny medal waiting for you at the finish line!
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Pair entry details must be filled in via your RR account by the 27th August 2025. After this date there will be a £15 charge per person.
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The transfer deadline is 26 August 2025. You can find more information on our transfer policy HERE and submit a request via your RR account. We are unable to process any transfer requests or make any exceptions after the deadline has passed.​
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Toilets are available at the start, finish and all pitstops.
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Waymarking: This event is fully waymarked, please do not follow any GPX routes.
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Road Safety: This event takes place on public paths, shared access trails and live roads. There are no closed road sections please always exercise caution.
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Route: We have strict arrangements and routings agreed with landowners and authorities, it is important that you follow all RR signage you see including instructions. If we ask you to close a gate behind you please do!
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Supporters are unable to access the start line as this is on private land with no parking available. Please see our recommended access points for your supporters further in this document.
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The finish is at Bron y Feds Uchaf, Rhyd Ddu (LL54 7YS​)
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​Emergency Contact numbers and information for during the event only is printed on the reverse of your bib number
TRACKER COLLECTION
HOW TO GET THERE
Tracker Collection is on Friday 26th September between 1500 - 2100 at the Harbour Office, Slate Quay, Caernarfon LL55 2PB.
Parking is available right next to the Harbour Office.​​​​​
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REGISTRATION STEPS
1) Bib Number -You will receive your bib number through the post 1-2 weeks before the event. International participants will need to collect their race packs in person on 26th September from the information/help desk at Tracker Collection.
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2) Disclaimer - Show your online disclaimer confirmation email at the entrance of Tracker Collection and receive your S2S: Yr Wyddfa Rat Rag. You can complete the online disclaimer now HERE, it takes 2 mins and we encourage you to do this now and certainly well in advance of the event to avoid any delays for you on the day.
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3) Tracker Collection - You will be issued your tracker from Open Tracking. There will be a link available on the website closer to the event for you to share with friends/family so they can track your progress over the weekend. There is some important guidance on the trackers below so please do ensure you read this. You MUST bring your running backpack to Tracker Collection so your tracker can be taped on when allocated
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4) T-shirt collection - If you have pre-ordered a t-shirt, you will be able to collect this from the onsite Rat Race Store.
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It is REALLY important that you ensure anyone watching at home knows this, for their own peace of mind and for our own safety systems. Experience shows that if someone watching at home does not understand this, they can sometimes unwittingly commence full rescue missions by panicking, calling in the cavalry and sparking confusion for us as organisers. As such, it really is a very important point to note.
You must return this device at the end of the event there is a charge levied of £150 for any tracker that is not returned.
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We recommend that people use the Open Tracking website and not the app for the best experience. The tracking link can be found on the Sea to Summit website closer to the event.
TRACKER
You will be issued with your Tracker from Open Tracking at Registration.
The trackers rely on GSM & satellite signal to report, (which is generally very good across a lot of our route) but there is a delay on tracking. Sometimes, our team back at base will increase or decrease the reporting frequency, so those watching at home will sometimes not see your dot moving, or see you moving very slowly. Or they may see you adrift from others in the group (for example if you have not turned the tracker on!).
PRE-ORDERED T-SHIRTS
If you pre-ordered an 2025 event tech t-shirt, these will be available for collection at the finish line! The size you selected will be printed on your bib number.
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IMPORTANT: Pre-ordered t-shirts must be collected at the finish line. If you do not collect your t-shirt, you will need to pay for this to be posted out to you after the event.
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INCIDENT CONTACTS DURING THE EVENT
1. For all incidents contact the Race Director or Medical Team
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2.Failing this, in the event of a true emergency or serious incident call 999....then inform the Race Director or Medical Team
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NOTE: Emergency numbers are issued in the one week to go email and at Tracker Collection. Text or call back if you do not get through. DO NOT leave voicemails. The Rat Race phoneline is only active during this event.
KEY INFORMATION
KEY LOCATIONS
Tracker Collection: Harbour Office, Slate Quay, Caernarfon, LL55 2PB.
Start: Caernarfon Castle, LL55 2AY
Finish: Bron y Feds Uchaf, Rhyd Ddu (LL54 7YS​)
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START TIME
There will be a mass start at 06:45. Please aim to be at Caernarfon Castle at 06:15 so you can be relaxed and ready for the start.
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GETTING TO THE START LINE
You can park at the finish line on event day morning by grabbing a parking pass for £10 per car (via your RR account) and then hopping on our shuttle bus from the finish line to the start line. You can book a seat for £10 per person (via your RR account). This will get you to the start line on time and mean when you cross the finish line, you are in close proximity to your car. You need to purchase a car parking pass (one per vehicle) and a shuttle bus ticket (one per person) to utilise this logistic.
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Bus tickets MUST be pre-booked in advance via your account.
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OTHER OPTIONS FOR GETTING TO THE START
Drop Off - You can get dropped off at Caernarfon Castle by a supporter. The best postcode to use for this is LL55 2NF. There are many car parks for supporter to use after drop off. The best postcode to use for this is LL55 2PB.
Taxi - We will be running a taxi service back to Caernarfon from the finish line after the event which will be bookable at Registration on a per seat basis.​
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BAG DROP
If you wish to use our bag drop service, you can leave one bag at the start line, this will be transported to the finish line for you. Please do ensure that your bag is waterproof as it may be exposed to the elements for all or part of the day. Please also ensure you bag is labelled with the bag tag included in your adventure pack.
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​FINISH LINE PARKING & MORNING SHUTTLE
You can park at our finish location (£10 per car) on event morning. This can be booked via your RR account until 8th September. Online sales will then close but parking can still be purchased from Tracker Collection.
You can then either purchase a seat on our morning shuttle bus service from the finish line to the start line or alternatively you can have a supporter or taxi (you will need to book this yourself) drop you off at the start line. We can recommend CK cabs who we have used on past events, bookable by calling 01286 871768.​
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Shuttle bus NOW SOLD OUT
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Supporters will be able to park at the finish free of charge when collecting participants on Saturday afternoon.
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The car park will open at 0500 and the buses will leave at 0600 for the 20 min drive to the start at Caernarfon castle.
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The shuttle will depart from Bron y Feds Uchaf, Rhyd Ddu (LL54 7YS) The google pin for this location is HERE. The what 3 words location for this is frowns.expecting.wins.
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If you purchase either a parking pass or start line shuttle bus ticket, you will receive passes for these in your adventure pack.
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ACCOMODATION
There are lots of local options available. If you want to stay near the startline we would recommend booking accommodation in Caernarfon. If you were looking for accommodation near the finish there are a few local B&Bs in Rhyd-Ddu or you’re up for a drive there are more options available in Beddgelert or Llanberis.
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FINISH LINES NOT FINISH TIMES
At Rat Race we are all about finish lines not finish times, our events are not races they are adventures designed for everyone to come and have a go at. We will provide an overall finish time, but it will not be split by gender or age category and there are no podium positions.
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MANDATORY KIT LIST
Taking on Sea to Summit: Yr Wyddfa is no small feat and you need to ensure you are fully prepared and kitted up for the ascending adventure from the shores of Caernarfon to the highest point in Wales!
The weather in the Snowdonia, even in September, is notoriously unpredictable. Clear skies can quickly turn into heavy rain, strong winds, and low visibility. Temperatures can drop significantly at higher altitudes, and underfoot conditions may include slippery rock, bog, or loose scree. For context, we had hail and freezing conditions on the summit in 2024, this could well re-occur in 2025. It is essential that you are prepared with the right kit and you should not go light on layers!
The mandatory kit requirements are in place not only to give you the best chance of taking on the adventure but ultimately for your safety. Should you be unable to continue the event and require assistance, the correct equipment will help ensure you remain as safe, warm, and dry as possible while waiting for help. This is particularly critical in remote or exposed areas where delays in reaching you may be unavoidable.
Spot checks will be carried out throughout the event at pitstops. Any #ratracer found without the mandatory kit will not be permitted to continue. These rules are non-negotiable and are designed to protect both you and our event staff.
Please review the full kit list carefully and ensure you carry every item. Your preparation could make all the difference—not just for finishing the challenge, but for staying safe while doing so.
KIT CHECKS
We have outlined why carrying each item of the mandatory kit is essential for your safety and success during the event within the document above. Please be aware that there will be random kit checks at various pitstops, with a particular focus at Pitstop 2/3, where we will be checking for waterproofs before you head for the summit. We reserve the right to check any item of mandatory kit during the event and you will be unable to continue should you not have required kit.
OUT ON THE ROUTE
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WAYMARKING & GPX FILE
The GPX file is now available HERE. It is important to remember the orange waymarking arrows always take precedence over the GPX file. If the two are ever in conflict, follow the arrows as it may have been necessary for the event team to make small live dynamic changes on the route e.g. fallen tree.
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​You will be shown examples of our waymarking at the start line briefing. This is predominantly hi-vis ORANGE arrows with the RR logo on, in addition you may see large hi-vis orange and yellow information signage or race tape. This will always have the RR logo on, please do not follow any signage that doesn't.
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YOUR SAFETY ON ROADS
When running on public roads you should face oncoming traffic and travel in single file (on the right hand side). However, should you be approaching a blind bend or rise, carefully move over to the other side of the road temporarily. Our signage and marshals will occasionally direct you to do this too, please follow their instructions. Should there be two-way traffic we ask that you stop to allow the car to pass you, ensuring you do not force the car behind you into the path of oncoming traffic. If there is a path available please use it.
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THE ROUTE
At 29.2 miles and over 5900ft of ascent this is a beast! The route will be fully waymarked so, follow the arrows! We thoroughly recommend you keep your head up not only to see the signs but to also appreciate the magnificent views!
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PIT STOPS
​There will be 3 Pit Stops at approx 6.7 miles, 12.6 miles and 20.8 miles. These will be stocked with an array of tasty small snacks, including hot drinks but please note this is not a full lunch provision, you should bring your own supply of food with you and use our stations as top ups! We endeavour to cater to a wide range of dietary needs but due to the nature of operation we are unable to guarantee there is no cross contamination. If you have a severe allergy we recommend bringing your own stash with you.
We do not provide sports nutrition products at our Pit Stops as these are a personal choice and you should have tried and tested supplements with you.
CUT OFFS
Cut offs are enforced and they are applied to your departure time not your arrival time into the location. If you are cut off you will be transported forward on the course using our sweeper vehicle. If you have supporters they can pick you up if you wish.
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Start: 0645.
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PS1 - 6.7 miles. No cut off.
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PS2 – 12.6 miles. Cut off 11:15**
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PS3 – 20.8 miles. Cut off 13:45. This is your last pit stop before your ascent of Yr Wyddfa.
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Finish – 29.2 miles.
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** At Pit stop 2, anyone can choose to take the short route to the summit of Yr Wyddfa from here, making the total distance 20.5 miles with 5175ft of ascent and still complete your sea to summit mission. Everyone who misses the cut off at PS2 will take this route to the summit.
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DROPPING OUT
Once you have started, if you wish to drop out of the event at any point you must contact the Race Team to inform them and return your tracker to a member of staff, even if you do not need further support from us. If you do not have your own pick-up option (eg a support crew with you) we will arrange to collect you and move you forward along the course. We cannot move you backwards. Race Team numbers are supplied at in the one week to mail and during tracker collection.
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COURSE ETIQUETTE AND LIVESTOCK
Please ensure all gates are closed behind you and never climb over locked gates. This is to ensure livestock do not escape fields so please do not leave it open for the next runner unless they are right behind you.​
RESPECT
Consider the local community and other people enjoying the outdoors. Take great care when passing near other tourist walkers, not to cause them to take hurried steps to avoid you. Hail them and enable them to step onto secure ground OR that you pass around them beside the trail.· Leave gates closed and property as you find it and follow paths unless wider access is available.​
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EVENT PHOTOGRAPHY
The MyBibNumber team will be out on course snapping all your best moments as you make your way to the highest point in Wales!
Sign up via the link HERE to be first to see your event photos when they go live and get a 10% discount on your digital downloads!​
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LITTER
Please help us leave this beautiful part of the country litter free by ensuring you have a pocket ready for your on the move rubbish which you can then dispose of at the next Pit Stop. We will gladly take this from you, if you see a discarded gel or sweet wrapper we ask that you pick it up on behalf of your fellow #ratracer who we are sure dropped it by accident.
TOILETS
There will be toilets at all 3 pitstops.​
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PERIOD PRODUCTS
We’ve got your back—period! In our ongoing drive to increase female participation and inclusivity in our adventures, you will now find disposable sanitary bins in designated toilets and a box stocked with period products at every location where we provide toilet facilities because let’s face it, surprises are only fun when they’re cake-related! Whether you planned ahead or got caught off guard, we’ve got you covered so you can focus on what is important, enjoying the adventure ahead. If you ever reach a pitstop and cannot see these products, please ask a member of the crew who will be able to point you in the right direction!
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SUPPORTER INFORMATION
SUPPORTER ACCESS
START, Caernarfon Castle
Caernarfon Castle is a cool place to start an event from. Spectators are allowed inside to cheer the runners. It has some great spot up the walls inside to cheer from. Just go exploring. Alternatively, you can cheer them on outside the castle as they exit the town. The best parking is on the harbourside at LL55 2PB. This has a 2.1m height barrier but there are many other car parks around Caernarfon. It’s a small place so nothing is ever far away. Everyone must leave the castle once the event has started.
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PS1, Snowdonia Slate Trail car park
There is no supporter access Pit Stop 1. It is located at the end of a 3-mile section of single lane country road, much of which is weaving and potholed. This road is also part of the event route, and it will be busy with runners. We want to avoid the additional congestion that would be caused by supporters driving this road and so we request that you DO NOT travel to PS1.
PS2, Rhyd Du car park
All supporters are welcome to visit PS2. It is located in a public car park with many spaces and public toilets. Please obey all local rules / restrictions, parked within marked bays and pay any required parking charges. You can find the car park HERE.
PS3, Llynd Isaf
Supporters are welcome to visit PS3 on foot. Supporter parking for PS3 is located at Nant Gwynant car park, a 400m walk from the Pit Stop. You can find the car park HERE and you will find the Pit Stop by walking back along the route.
Along the route
There is a good opportunity to offer support between PS1 and PS2 in Beddgelert at 17.5 miles.
Please note, we don't have a designated support point at this location. Please park responsibly and be courteous of residents.
FINISH, Private Field near Llan Cwellyn
Supporters are welcome to access the finish. All vehicles require a parking pass, you can purchase these via your RR account.
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VOLUNTEERS & MERCH
GOT A SUPPORTER WHO WOULD LOVE TO JOIN THE CREW?
We're on the look out for some extra volunteers to help during Registration, man the finish line handing out medals and also cheer you all on at the Pit Stops. Volunteers help contribute to the amazing, friendly atmosphere you'll find at Sea to Summit: Yr Wyddfa and they have an incredible day supporting our #ratracers to boot.
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As a volunteer you will receive:
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£50 cash travel contribution
£150 event credit
A crew Rat Rag
Access to hot drinks/snacks/food
A fun day out!
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AVAILABLE SHIFTS
You can sign up to any available shift here and the Rat Race team will be in touch ahead of the event to answer any questions you may have and give you your briefing documents.
ANY QUESTIONS?
CUSTOMER SERVICE
If you have any questions not answered in here please do reach out to us on events@ratrace.com and our friendly team will get back to you as soon as we can!
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TRANSFER ENQUIRIES
If you need to withdraw from Sea to Summit: Yr Wyddfa and go through our transfer process this closes on the 26th August. After this time we cannot process any transfer requests. For all the information regarding transfers please click here.
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PAIR/TEAM ENTRIES
If you are a part of a pair entry please ensure both your details are filled in before the 26th August 2025. Any late submissions will be subject to a £15 admin fee to create your Adventure Pack on the day. Just login to your Rat Race account to add these details.