The ‘ULTIMATE"‘ challenge awaits

Big ultra-marathon swim challenges like the English Channel can be very difficult to organise, often with long waiting lists or expensive solo organisation costs. Whether your aspiration is to take on an iconic Channel swim in the future, or you relish the idea of an ultra-marathon challenge, without the hassle of organising it, UltraSwim 33.3 now has two big swim options added to its beautiful Croatia event each May (only).

Its headlined by a 33.3km single non-stop swim between the two stunning ancient 12th century villages of Stari Grad, and Hvar Town - literally from village centre to village centre. Stari Grad entered the International Swimming Hall of Fame for the Pharos Swim Marathon - and you’ll start just after sunrise from there, our starting base for the overall UltraSwim 33.3 - you’ll finish 33.3km later in the centre of lively Hvar Town, via 10 stunning peaceful bays and Pelegrin lighthouse, to celebrate an epic achievement!

As a stepping stone up to the ULTIMATE 33.3, we also offer the shorter ULTIMATE 22.2 - still non-stop - but finishing in Stiniva Bay - still a big step up for those who’ve previously done impressive but shorter marathon swims around 10km.

If already the 33.3km over 4 days seems plenty (quite normal!), then the rest of this is maybe not for you (yet) - but why not get that 'end of winter' (if you're a northern hemisphere person!) challenge of UltraSwim 33.3 #12Croatia booked and have a big hairy goal to aim for!

Entries to the ULTIMATE are strictly limited and you should book early to avoid disappointment.

The ULTIMATE swims will take place usually on Day 2 (Saturday) with Sunday being a reserve day in case of adverse weather. Both courses start in Stari Grad harbour on the famous Pharos Swim Marathon startline, just after sunrise, and the cutoff times mean you will finish in daylight. A minimum pace of 2.3km/h is required for the ULTIMATE 33.3 swim and 2km/h for the ULTIMATE 22.2. A dedicated boat and skipper will be provided as part of an extensive ULTIMATE support package.

Choose from 2 entry packages:

  1. #12CROATIA full event entry PLUS ULTIMATE (22.2 or 33.3) OR

  2. ULTIMATE (22.2 or 33.3) ONLY

OPTION A means you have the full event benefits, option to swim all the other days of the normal UltraSwim 33.3 event, and you just swap the Saturday for the ULTIMATE 22.2 or 33.3. It means you have 4 nights accommodation, all the massage and lunch benefits each day, and the flexibility to swim when you want on the other days. It means an ULTIMATE 22.2 swimmer can also make it to the 33.3km Finisher distance by combining with two of the other normal event swims.

OPTION B means you are only swimming on the ULTIMATE race day, plus if you want, the final day 4 swim and finale in to Hvar Town - as its too much fun for us to not allow you to!

You will be asked to bring your own support crew of at least one experienced person who will manage your nutrition feeds and overall well-being on the ULTIMATE swim. We’ll provide boat, skipper, live tracking, dedicated ULTIMATE Race Director, event medical team on standby and the course plus more!

What we will provide:

  • A dedicated ULTIMATE co-ordinator / Race Director

  • Personal support boat with skipper/observer, fuel included

  • Recce trip of the course on the Friday

  • Live tracking

  • Timing and results

  • MSF longswims database event registration request

  • Medical cover on standby

  • Full medical check by our on-site doctor

  • Precision Fuel & Hydration products for the swim

  • Support boat pack (coolbag etc)

  • ULTIMATE preparation webinar

  • ULTIMATE pre-event briefing & on site preparation session

  • Dedicated boat tracker and radio support on each boat

  • Remote monitoring of tracking throughout

  • Start and Finish lines

  • Dedicated WhatsApp channel for swimmers and support team, includes our Ambassadors input where appropriate

  • ULTIMATE specific Finisher medal / and prize giving (Sunday)

What you will need to provide:

One support person who has some experience of supporting you or another marathon swimmer on a 5 hour + swim - in particular who has the knowledge to manage your regular feeding routine. A second person may also be on the support boat. Accommodation for at least one support person must be taken through us at the event hotels (for number of nights they require)

  • Any extra specific nutrition, fresh food and feeding equipment (eg feedstick if choosing to swim under MSF rules)

  • A medical certificate certifying fitness for the ULTIMATE swim*

  • Your mental strength and desire to finish!

* UltraSwim 33.3 will provide a medical certificate template which must be signed by a certified medical professional following an in-person medical;

Potential courses for the 33.3 and 22.2

Q&A on Croatia ULTIMATE 33.3/22.2

  • What day of the event will the ULTIMATE swim be? Normally on the Saturday, with Sunday as a reserve day. If you take the full event entry option you are free to swim the other races on Friday and Sunday, and all ULTIMATES are invited to swim the final day on the Monday.

  • What happens if the weather is bad, is there a risk like many other long distance challenges that I don't get to swim at all? This risk is very low as we have two days to be able to achieve this swim, plus many Plan B courses if required to keep out of the worst weather.

  • How experienced does my support person need to be? They will need to be practiced and comfortable managing your nutrition and feeding regime (generally swimmers are feeding every 30 minutes on such swims, we can provide more advice on this of course), and equally have some experience on how to maintain both safe distance and correct protection for the swimmer to ensure the skipper acts as you require him to. It’s possible we could provide someone - but at an additional cost - if you don't have this support person yourself.

  • How fast do I need to swim? With almost mid-summer daylight hours, the minimum average pace required will be 2.3km/h for the ULTIMATE 33.3 and 2km/h for the ULTIMATE 22.2 - if you cannot hold this pace, you will need to exit the water when asked. Allowance will be made for adverse current and conditions, with start / finish times adjusted accordingly - but there will be no swimming outside in the dark.

  • Can I bring more than one person with me? Yes the boat that will be dedicated to you will have the space for 2 or 3 support crew, we just ask that at least one of the support team takes our partner hotel and transfer package (at the same level as you)

  • How late can I leave it to book? Places are strictly limited (by the ability to source appropriate support boats and skippers) so you are advised to secure your space as soon as possible via www.ultraswim333.com/enter pay your event deposit and send us your marathon swimming resumé on epicswims@ultraswim333.com for us to consider.

    How much does it cost ?

    Option A - UltraSwim 33.3 #12 Croatia Entry Standard event 4 night entry package of your choice

  • (ULTRA €1,800, ULTRA+[4*] €2,600, ULTRA+[5*] €4,100, ULTRA++ €7,500)

  • Plus ULTIMATE Supplement (€1,500)

  • Plus Accommodation package for support person (€500-€750)

    Option B - ULTIMATE 22.2/33.3’ Dedicated Package Based on normal ULTRA+[4*] event package

  • 4 nights accommodation for swimmer + support person

  • Transfers from airport-Split-Hvar included

  • €4550 total price

Booking conditions for the ULTIMATE are different to the main event package, see the download package for more details.

“I have been completely overwhelmed since it finished and can’t quite believe what I achieved. So thank you for giving me the opportunity, as it has served as amazing training in preparation for my English Channel swim later this year.”
— Su, UNITED KINGDOM Successful ultimate 22.2 May 2025 in 09hrs 32mins
“Thank you for all your hard work organising a fabulous event. I would never have been able to organise a such a swim so far from home without your help, and am so very glad to have had to chance to swim in such a special location”
— Anna S, australia Ultimate 33.3 competitor 2025