Are You Ready to Conquer UltraSwim 33.3?

33.3km over 4 days is a daunting challenge for most swimmers. Good preparation is needed and you must be determined, however don’t be intimated. Our experts (and other swimmers) are here to support you and our events see swimmers with a wide range of experience complete the 33.3km distance - many not sure before they start.

We get asked this question a lot.

‘How good of a swimmer do I need to be to take on the UltraSwim 33.3 challenge?’

in theory it’s simple… if you are a competent swimmer, prepare well and are determined, you belong at our events.

But to save the overthinking, we’ll break it down for you…

We think you’re ready if:

Pace

You can swim at least 2.5km in an hour in a pool (this will translate to potentially 2 kilometres per hour over longer distances in open water which is our on-water cut off pace in good conditions)  

Endurance

You’ve comfortably managed a 3km swim or more, in open water before you come to the event

Commitment

You are committed to training and preparing. You might not have all the requirements but with coaching, training, and commitment you will get there. You should feel some discomfort when you enter - that’s normal!  

Open water

You’re comfortable in open water, even when it’s not totally flat (again, you don’t need loads of experience, just a small amount)

Front crawl

You can swim front crawl continuously, our event isn’t suitable for breaststrokers unless your pace is exceptional. We’ve had breaststrokers take part but, again, unless you are extremely competent, it’s not advised.

You don’t have to be an elite swimmer to be a winner at UltraSwim 33.3. And we mean that. Just getting to the start line is already 90% of the work. We know (because we’ve seen it first hand) that with the right preparation, anyone can become a 33.3 Finisher. And you know what, even if you don’t make finish line of every single swim, you’ll be enormously respected for what you’ve achieved, regardless. Swimming might be a ‘solo’ activity, but at our events, it is more like a team sport, with everyone helping each other out and supporting one another. You’re going to find your tribe early on and work together!

If it’s still too daunting for you to imagine doing the 33.3 CLASSIC, there is also the ‘Half Channel’ 33.3/2 BUILD
- its like we dropped you in mid-Channel and you’ve still got make it to France!

MORE ON 33.3/2 BUILD option: longest single swim 5km

“We always try to encourage swimmers to take on the full 33.3km challenge because time and again, we’ve seen that most competent swimmers can push beyond their perceived physical and mental limits, also carried by the incredible energy of the 33.3 tribe, and nail the full 33.3. However, we also recognise that some swimmers prefer to set themselves a slightly less demanding goal - while still achieving an impressive swim. That’s why we created the ‘Half Channel’ option, known as 33.3/2 BUILD: to offer a stepping stone or a more measured challenge within the UltraSwim experience.”
— Mark Turner, Founder, UltraSwim 33.3

33.3/2 BUILD Option – Step Up Your Endurance

Perfect for swimmers who want to build toward longer distances, the 33.3/2 BUILD option covers 3-5km per day over four days. You’ll experience key highlights of the full challenge, including:


✔️ The longest swim on Day 3, alongside the full-distance swimmers, where you'll push past previous limits.


✔️ This is NOT a competitive race format - no rankings or podiums - but you’ll still be a proud ‘half Channel’ Finisher if you make all the swims inside the 2km/h cutoff

✔️ Experience tells us you’ll be back the following year to take on the full 33.3 CLASSIC!

What does a 33.3/2 BUILD day look like? 

There is no difference in the experience, information provided or price for 33.3/2 BUILD compared with the full 33.3 CLASSIC - but the swims you will take on are of course shorter each day, and are part or all of the full course depending on logistical or weather constraints. You'll sometimes start with the 33.3ers and other times finish with them. 

See below an example of the planned swims in #7Croatia in 2025 [NB until #10 this format was known as 11.1 and 22.2 - these have been combined in to one shorter format for 2026]

✨ “The first 22.2 I swam was magic as it made me (and Marie) feel that it was doable!” – Karen Heng, UK ✨ Karen then went on to complete very well her first full 33.3 at #5Montenegro 2024, and has been back 3 times since ✅