It’s not for everyone.
But everyone can do it!
UltraSwim 33.3 offers you the opportunity to complete the iconic 33.3km distance of the English Channel,
spread over 5-7 swims, over a 4-day long weekend, in an adventure swim point to point race format, in stunning locations around the world.
This is not your average sporting event, swimming 33.3km even over 4 days is a challenge for any swimmer,
and our races take place in varied and challenging conditions that will push you to your mental and physical limits.
We can’t guarantee you’ll become a 33.3 Finisher the first time around, but we can guarantee you won’t regret taking part.
With our flexible rollover policy, better to enter now and reserve your spot even if you are not 100% sure about your availability or event choice.
Join us at one of these upcoming events…
#7CROATIA
The ‘Islands’ Edition
16-19 MAY, 2025
Welcome to the sunniest island in Europe and the perfect way to start the open water swimming season in the northern hemisphere! Swim between two ancient villages, Stari Grad and Hvar Town, via hidden bays and dozens of islands, over a simply gorgeous 33.3km of crystal clear water.
#8SWITZERLAND
For Léman hope, the ‘Lake’ Edition
5-8 SEPT, 2025
Lake Geneva (more correctly known as Lac Léman) is nestled in between the Swiss and French Alps - with Geneva at one end and Chillon/Montreux 70km away at the other, and our base in Lausanne in the middle! This fresh water lake provides for incredible swimming, amazing 360 degree views, and UNESCO heritage vineyards rolling down to quaint lakeside villages. This first edition was open only to previous particpants of UltraSwim 33.3 as a Founders’ Pioneer event.
#9GREECE
The ‘Mamma Mia’ Edition
19-22 SEPTEMBER, 2025
Welcome to Greece’s greenest island, Skopelos in the Sporades archipalego to the north east of Athens - where the cult film Mamma Mia was filmed! The warmest water, and best Greek hospitality you can find. Sells out quickly each year.
#10MONTENEGRO
The ‘Fjords to the Sea’ Edition
Welcome to the original UltraSwim 33.3 Epic Adventure Swim Race™ location - Montenegro.
One of the smaller countries of the Balkans, #10Montenegro’s racecourse offers both wild mountain backdrops and deep fjords, as well as rugged Adriatic coastline, producing a variety of conditions. Highlights include swimming through an abandoned submarine pen and the iconic Blue Cave.
The water temperature is expected to be between 18-22°C
3-6 OCTOBER, 2025
Our recommended ULTRA+ package includes:
Entry for the 4-day event
Hotel 4* or 5* for 4 nights (based on double occupancy, single occupancy upgrade available)
Dedicated airport transfers
Pre-event coaching, preparation and support
Personal 1:1 video analysis pre-event
Breakfast and post-race refuel lunches included
Swimmers pack (dry bag, towel, water bottle…)
Post swim massages (Days 1-3)Preparation webinars and clinics
Optional family package (F3)
#12CROATIA
The ‘Islands’ Edition
Welcome to the sunniest island in Europe and the perfect way to start the open water swimming season in the northern hemisphere.
This racecourse takes swimmers between the two beautiful and ancient villages of Stari Grad (start) and Hvar Town (finish) via secret bays and stunning islands. What Croatian waters have to offer both above and below the waterline will blow you away.
The water temperature is expected to be between 18-21°C
15-18 MAY, 2026
Unique to our Croatia event
Start and finish in different villages -two venues to discover in one event.
One of our two ‘island’ events - take in the island vibe…
Half Board/dinner allowance included in ULTRA package for first 3 nights
Simply perfect Relais&Chateaux Maslina Resort for ULTRA+[5*] and ULTRA++
ULTIMATE 22.2/33.3 - non-stop ultra marathon add-on option only in Croatia
Two channel crossings of 2.3km each planned
Town centre finish on final day - with your non-competing partner if they want!
The longest daylight hours, 0530-2110
Pre-event preparation swim camp
#14SWITZERLAND
For Leman hope “The Lake edition”
Lake Geneva (more correctly known as Lac Léman) sits between the Swiss and French Alps, and the Swiss/French Jura - with Geneva at one end and Chillon/Montreux 70km away at the other. This fresh water lake provides an incredible swimming venue, with amazing 360 degree views, and UNESCO heritage vineyards rolling down to quaint Swiss and French villages on the lakeside. Lausanne the Olympic city will welcome you, with other iconic spots such as Montreux (of Jazz Festival fame), Chateau de Chillon, and Evian (France).
The water temperature is expected to be between 20-23C
4-7 Sept, 2026
Unique to our Swiss event
Our only fresh water venue
13km iconic country to country lake crossing to France (Lausanne-Evian)
Lausanne Olympic Musuem (right next to our venue) - great to visit post swim
Public transport focus - we’ll be using Swiss trains and the classic CGN lake ferries to move you around [worth using image of one here maybe not this one but one showing the vineyards too - see CGN]
Very well connected Geneva airport, with low cost flights, as well as great train connections in Europe (direct from Paris, Milan, Zurich, Munich…)
Swiss Franc pricing - this won’t be our cheapest entry costs, but the low cost travel options to get here should make up the difference for many
We (and you) will be raising money for local charity Leman hope, that helps rebuild confidence in young cancer survivors. CHF50 of your entry fee will already be donated.
#15GREECE
The ‘Mamma Mia’ Edition
Welcome to Greece’s greenest island, Skopelos in the Sporades archipelago - home also to the cult film Mamma Mia! You’ll be singing Abba songs whether you like or not all the way around!
This racecourse takes us around the unspoilt wild coastlines, both exposed and sheltered from a regular strong north wind and of course, passing the famous filming locations like the clifftop island church Agios Ioannis
The water temperature is expected to be between 22-26°C
18-21 SEPTEMBER, 2026
Unique to our Greek venue
Swim between film set locations of the Mamma Mia! film! …our 2024 Pioneer event fave spot? Mamma Mia church…
Our main hotel base, Adrina Resort, family owned and run, hosted the film stars…but more importantly we feel, is that its off-grid with own solar electricity, and installed a filtered water supply just for us (no need for the plastic bottles prevalent in Greece!)
Warmest water temperatures of all our events by quite a few degrees.
Island to island crossing from Alonissos to Skopelos and/or an island circumnavigation on final day
Statistically the windiest venue too, but also the warmest
Fly via Athens to visit the Acropolis!
#16MONTENEGRO
The ‘Fjords to the Sea’ Edition
Welcome to the original UltraSwim 33.3 Epic Adventure Swim Race™ location - Montenegro.
One of the smaller countries of the Balkans, #16Montenegro’s racecourse offers both wild mountain backdrops and deep fjords, as well as rugged Adriatic coastline. Flat calm fjord to challenging coastal course, this has it all, and the Lazure Hotel & Marina base in Melijne, Herceg Novi, serves possibly the best breakfasts of all our events - even at 0530am!
The water temperature is expected to be between 19-23°C
2-5 OCTOBER, 2026
Unique to our original Montenegro venue
This will be our 4th time around and still our favourite.
Weather permitting traverse of amazing ‘Blue Cave’ on startline of marathon swim day
Cold war era submarine pen as part of the course
2 channel crossings including a country to country 2km from Croatia back to Montenegro
Swim around Mamula prison island (now a 5* hotel) after lunch on it!
Only event with Age Group podium and prizes!
Indoor and Outdoor pools with amazing spa hotel
Pre-event preparation swim camp
WHAT’S INCLUDED?
Personalise your experience to fit your sporting ambitions, budget, time and family constraints.
Whilst the Classic 33.3 is our main sporting format, there are 3 other options, both easier and harder. Then are 4 different support and accommodation packs to choose from to suit your budget and style. Our recommended ULTRA+ package includes for example at the event:
Entry for the 4-day event, including a day0 warmup swim
Hotel 4* or 5* for 4 nights with single occupancy and partner package options
Early morning breakfasts and post-race refuel lunches (and some venues include half board)
Dedicated airport to/from event venue transfers, by land, water or both!
Post swim 25 minute sport massage (days 1-3)
Access to expert physio and sport injury expert on site
Swimmers pack (personalised dry bag, recycled micro-towel or poncho, reusable aluminium water bottle, wooly hat by RED or sun hat by FRACTEL)
Optional Supporter Activity package for Family, Friends or Fans (F3), and accommodation/transfer pack for those partners
Your journey to the UltraSwim 33.3 finish line though starts from the day you enter
#Virtual events to inspire your training
Preparation webinars and clinics on nutrition, general open water tips, sports injury pre-hab and re-hab, event briefings, wetsuit choices
A free copy of our digital magazine FLOW packed with advice and tips from open water swimming experts
Pre-event training plans, preparation and support group
Personal 1:1 video analysis pre-event (you send us the file, not for ULTRA)
Promotional discounts from our nutrition partners Precision Fuel & Hydration, custom made goggles from TheMagic5, super kit from our change robe partner RED, and high performance wetsuits from deboer. [ADD LINKS TO EACH PARTNER PAGE]
Free 20 minute nutrition consultation online with Precision F&H
