UltraSwim 33.3 Skopelos 2027: race guide

What it is and when it takes place

UltraSwim 33.3 is a series of multi-day, point-to-point warm-water open-water swimming events, based on a different island or coastal destination each year. The 2027 Skopelos edition is scheduled for 17-20 September 2027, based at the family-owned Adrina hotel group in Panormos — as the official 2027 edition page itself states.

Per the organiser's own 2027 calendar, this is "event #20" in the UltraSwim 33.3 series overall, counting every venue worldwide (Greece, Switzerland, Montenegro, Spain, the Caribbean) since the first test event in Montenegro in 2022. The organiser's own results archive shows Skopelos is hosting the series for a 4th straight year: #4 Greece in 2024 (13-16 Sep, 46 finishers), #9 in 2025 (19-22 Sep, 160 finishers), #15 in 2026 (18-21 Sep, 158 finishers), and #20 in 2027.

Two distances: 33.3 Classic and the newer 33.3/2 Build

The 2027 edition page explicitly lists two available formats: "33.3 CLASSIC" and "33.3/2 BUILD." Classic is the full 33.3 km distance — the organiser itself calls it "the theoretical shortest distance" of an English Channel crossing. Build is a newer, shorter format: the organiser's own events-overview page describes it as "the half channel option, covering half the distance (around 17km)" — roughly half the full route, not 16.65 km. (A similarly named "16.65 COMPACT FORMAT" also appears on the site, but it belongs to a separate, new two-day Barcelona event, not to the Skopelos Build format.)

The 2027 calendar page itself explains that this shorter format is also called the "Half Channel" and comes "at a 17km distance over four days, available everywhere except Milos" — meaning Skopelos offers both options, while the sister event on Milos (see below) offers only the full Classic.

How the distance "builds" across 4 days

UltraSwim 33.3 is not one continuous swim, but a series of individual "swims" spread over 4 days — the series' general description (not Skopelos-specific) talks about "5 to 7 swims" that progressively "build" the distance: shorter swims on the earlier days, with "a 10km plus marathon day usually on the third day, when you are feeling stronger and more confident," and a lighter, more "celebratory" final day.

For the specific Skopelos 2027 edition, no official page yet publishes a detailed day-by-day schedule with per-leg kilometres — only two facts are given as "specific to this event": "at least one island to island crossing planned" and an optional evening swim, weather permitting (the dedicated 2027 page calls it a "night swim," while the 2027 calendar overview page calls it a "sunset swim" — the organiser's general FAQ also describes this feature series-wide as a "sunset or night swim," so the two terms may simply be used interchangeably rather than reflecting a real inconsistency).

For a sense of what the first Skopelos edition (2024) actually looked like, a Skopelos tourism site (skopelos.com, not the organiser itself) described: day 1 from Gourouni Lighthouse to "Mama Mia Beach" (about 8 km); day 3 from Adrina Resort toward the Mplo cove; day 4 around the small island of Dassia, finishing at Adrina Beach Hotel. That is historical detail from 2024, not a confirmed 2027 schedule.

Panormos, Adrina, and the water around Skopelos

The event's base is Panormos, on Skopelos's west coast, at the hotels of the Adrina group — a family-owned chain the organiser itself describes as the "waterfront Adrina group of family owned hotels." Water temperature is given as 23-26°C on the official 2027 edition page. The organiser's own 2027 calendar page additionally describes it as "the warmest of any European venue" — a claim that page appears to contradict itself on, since it lists the same 23-26°C figure for its freshwater Swiss venue too.

The 2027 calendar page also describes Skopelos as "the most remote" venue on the calendar, with beaches and bays "reachable only by sea" — and gives, on that same page, the most specific 2027 route description found: "The 33.3km circles the greenest island in Greece, passing the clifftop Agios Ioannis church of Mamma Mia fame" (the dedicated 2027 edition page itself contains none of these phrases, only the water-temperature figure).

The "Mamma Mia" theme: what the organiser itself says

The "Mamma Mia Edition" name is official — it appears as the edition's own title in the organiser's 2027 calendar, following the same naming convention the series uses everywhere (Milos is "The Aphrodite Edition," Switzerland "The Lake edition"). The theme is not new to Skopelos: in the organiser's own recap of the first Skopelos edition in 2024, the founder wrote "Mamma Mia, here we go again" as the team's rallying cry heading into what was then an "untested," unknown island.

The Agios Ioannis Kastri chapel the official page names is indeed known as "the Mamma Mia church": built on a rock roughly 100 metres above the sea, it is where the wedding scene of the 2008 film was filmed — per the regional tourism portal Visit Thessaly (not the organiser).

History: Skopelos in UltraSwim 33.3 (2024-2027)

Skopelos joined the series in 2024 as a "new venue" — the organiser's own post at the time described it as "untested waters, new relationships with suppliers, hotels, boat captains." The organiser's results archive gives 13-16 September 2024 for that first edition, with 46 official "finishers." The organiser's own event recap, in the founder's words, separately states there were "61 paying clients" at that first Skopelos edition; a Skopelos tourism site independently gave the same figure as "sixty-one swimmers convened on Skopelos" — a figure that most likely counts everyone who started, not only those who completed all 4 days. Neither figure is necessarily in conflict with the official 46-finisher count, but this article keeps them separate rather than merging them into one.

Subsequent editions grew steadily: #9 Greece in 2025 (19-22 September, 160 finishers) and #15 in 2026 (18-21 September, 158 finishers) — roughly triple the finisher count in year two versus year one, with 2026 landing at nearly the same level as 2025. 2027, under the "Mamma Mia Edition" name, is the series' 4th consecutive year on the island.

Where the 33.3 km distance comes from: Captain Webb

The organiser explains the name's origin on its own page dedicated to Captain Matthew Webb: Webb began the swim on 24 August 1875 and completed it at 10:41am on 25 August 1875 (about 21 hours 45 minutes, "almost 22 hours"), becoming the first person to swim the English Channel unaided, from Dover to near Calais, swimming breaststroke through cold water, strong tides and stinging jellyfish. The same page defines the Channel as "the 33.3km stretch of water between England and France at its shortest crossing — the distance behind every UltraSwim 33.3 event."

The same page states that "UltraSwim 33.3 was established in 2022 to swim the iconic English Channel distance of 33.3km, but spread over four days in warm water rather than a single night," and that Webb's motto, "Nothing Great Is Easy," "has become ours." The same page also credits Gertrude "Trudy" Ederle, the first woman to swim the Channel, on 6 August 1926, in 14 hours and 39 minutes — faster than any of the five men who had managed it before her, swimming front crawl through a rising storm.

Registration, cost and requirements

The 2027 edition page lists pricing "from €1,969," with a fully refundable €500 deposit through an online booking form. The organiser's own all-events overview page, however, gives a different "from €1,794" figure for the same Skopelos 2027 edition (grouped together with 2026) — two official pages from the same organiser disagree on the number; bib2bib does not pick which is correct and recommends checking the live price directly before paying any deposit.

The series' general entry requirements (not Skopelos-specific) ask every participant to be able to "swim 2.5km in a one hour pool or flat water time trial" and to have completed "at least one 4 to 5km open water swim" in training beforehand. The pace guideline is "never more than 2km per hour," adjusted for conditions — anyone missing a cutoff can still continue the remaining swims, just without an official ranking. Wetsuits are permitted but not required; a swimmer's ranking category depends on whether they start in skins or a wetsuit.

For water safety, the series describes transfer boats that stay with swimmers, "significant numbers of kayaks and paddleboards" alongside and waiting at key turning points, a Race Director RIB, and a dedicated medical support boat — every swimmer wears a GPS tracker and is monitored through "SwimTelligence 2.0" software.

Skopelos vs Milos: the sister UltraSwim event in Greece

Greece hosts two UltraSwim 33.3 editions in 2027: Milos ("The Aphrodite Edition," 3-6 June 2027, based in Pollonia) and Skopelos ("Mamma Mia Edition," 17-20 September). The main distance difference: Milos, per its own official page, offers only the full 33.3 Classic — no Build/Half Channel format is listed there — while the 2027 calendar page itself explains the 17 km "Half Channel" "is available everywhere except Milos." Skopelos is therefore the Greek option for anyone who wants either the full distance or the shorter format.

Water conditions differ noticeably too: Milos is listed at 20-22°C in early June, while Skopelos sits at 23-26°C in September — tied with the series' Swiss freshwater venue for the warmest figure among the 2027 European editions, per the organiser's own calendar page. Both Greek editions share the series' general design (4 days, a progressively building distance, a "marathon day" around day 3) and the same water-safety model, but differ in scenery, theme ("Aphrodite" versus "Mamma Mia") and pricing.