The Course: A Flat Out-and-Back From the Beach
The race starts and finishes on Bangsaen Road 1 in front of the Bangsaen Heritage Hotel [1]. The organiser's route runs from there down to the beach road, along Bangsaen Road 2 and the Bangsaen-Ang Sila road onto Road 3134, and out to a U-turn at the Phraya Satcha junction; it comes back the same way, then goes round Khao Sam Muk and returns to Bangsaen Road 1 for the finish [1]. The timing splits put the U-turn at 10.3 km [2].
It is flat. The organiser's GPX file of the 2025 course, which measures 21.3 km on GPS, never rises above about 27 m [3]. There is a small rise at about 8 km that runners meet again at about 13 km on the way back, and the highest point comes late, at about 16.6 km [3]. In 2025 the host municipality put the race mascots, the monkeys Sammy and Mukkie, at Khao Sam Muk, lit the route and asked residents to come out and cheer [4].
The distance is 21.0975 km and the race is a World Athletics Platinum Label road race [1]. The course page notes that the route and service points are subject to change [5].
The Weather: Drier Air Than Most Races in the Region
Suvarnabhumi airport, about 48 km north-west of the start, recorded 24°C at 4am on race morning, with a dew point of 18°C, 69% humidity and a 5-knot wind [6]. It cooled slightly to 23°C from 6am to 7.30am and was 25°C at 8am, when the course closed, with the dew point at 17°C and 61% humidity [6]. U-Tapao airport, about 69 km south on the coast, was cooler and damper: 22°C with a dew point of 20°C and 88% humidity at 4am, 20°C to 21°C through the dawn, and 24°C with 65% humidity at 8am [7].
A dew point between 17°C and 20°C is noticeably easier to race in than one in the mid-20s, because sweat can still evaporate. For comparison, the same Suvarnabhumi station recorded 27°C with a dew point of 26°C and 94% humidity at 2.30am on 9 November 2025, the morning of the Bangsaen42 marathon on the same roads [8]. That was one year's weather, not a guarantee.
The race director said after the race that "New PB" could be heard everywhere in the first half hour after the finish, and that this year's top-100 times were faster for both men and women [9]. The top-100 figures bear that out: 1:21:27 for the 100th man and 1:42:40 for the 100th woman in 2025, against 1:24:39 and 1:47:00 in 2024 [10].
Aid Stations, Cut-offs and the Start
The route map on the course page, which is labelled for the 2026 race, marks the first water at about 4 km [11]. Most stations sit on the out-and-back, so runners pass them twice: at about 4.8, 6.5, 8.0, 8.6 and 10.1 km on the way out, 12.1, 12.7, 14.1 and 15.8 km on the way back, then 18.2 and 20.2 km, with the longest gap, about 2.4 km, between 15.8 and 18.2 km [11]. The map also shows 12 toilet points and 11 medical points [11]. Before the 2025 race the medical director said there would be 39 defibrillators, advanced ambulances and a team of medics running the course [4].
In 2025 the results point to three waves, at about 4.00, 4.15 and 4.30am, and to a limit of three and a half hours from each runner's own wave: the last ranked runner finished at 7.59am, and 37 runners who took longer than 3:30 from their wave start are listed as incomplete [2]. Two runners were disqualified for crossing the start before their wave [2].
For 2026 the organiser has moved the waves to 4.15, 4.30 and 4.45am and counts the three-and-a-half-hour limit from the last wave [1]. The start line closes at 5am, and there are cut-offs at 10 km (6.30am), 15 km (7.16am), 20 km (8.03am) and the finish (8.15am) [1]. Runners are not allowed to continue past a cut-off; a sweep shuttle takes them back, and they get food and drink but no medal [1]. Left baggage opens at 2am [1].
Closed Roads, Strict Rules
The mayor of Saen Suk, the host municipality, said the roads would be 100% closed to traffic for the 2025 race [4]. The 2026 schedule reopens them at 10am [1].
Entry rules are strict. In 2025 registrants had to upload a front-facing photo, check-in at race-kit pickup used a face ID system, and bib transfers were banned under any circumstances [12]. The minimum age is 19, counted by year of birth, and the organiser does not let younger runners take part [1][12].
How Fast the Field Is
Kenya's Samwel Nyamai Mailu won in 1:02:59, ahead of Ethiopia's Teresa Nyakola Gela (1:03:22) and Seyoum Beharu Regasa (1:03:36). Dolphine Nyaboke Omare of Kenya won the women's race in 1:10:14, from Ethiopia's Beriha Gebreyohanes Gebreslasie (1:11:12) and Mehret Gemeda Robe (1:12:30) [9]. Nattawut Innum was the first Thai man in 1:10:09, a seventh Thai title in a row, and Pareeya Sonsem the first Thai woman in 1:22:05 [9]. Berlin Marathon race director Mark Milde also ran [9].
Neither winner came near the course records of 1:01:56 and 1:07:45 [1], both set at the eighth edition by Kenyan runners, the women's by Hellen Obiri [13]. The 2025 host municipality offered bonuses of more than 600,000 baht in total for foreign and Thai runners who broke a course record or a Thai record [4].
Behind the elites the field is deep. Tenth place was 1:12:14 for men and 1:25:33 for women, net [2]. 312 men and 14 women ran under 1:30, and 2,977 runners broke two hours; the median finisher took 2:19:55 [2]. The Sammy and Mukkie trophies go to the fastest 100 men and 100 women aged 19 to 59 and the fastest 10 aged 60 to 69 [1]; in 2025 the tenth senior took 1:37:51 for men and 2:06:01 for women [10]. There is prize money for the overall top five, from US$10,000 for first in 2026, and a separate Thai top five from 30,000 baht [1].
The field is overwhelmingly Thai. Of the finishers, 10,142 carried a Thai flag in the results; most of the rest came from 36 other countries, led by Japan, Malaysia and Indonesia [2]. There were 7,390 men and 3,005 women among the finishers [2].
Getting a Place and Race Weekend
Most Thai places are drawn by ballot. In 2025 the general round picked 4,000 runners at random [14]. The ballot page gave the normal fee as 2,000 baht, with 1,400 baht for loyalty runners who collected their bib on Friday 19 December between noon and 8pm only, or 1,600 baht to collect on Friday or Saturday [14]. International runners had a guaranteed entry at 1,800 baht, or 3,000 baht as a semi-elite with a half marathon under 1:20 for men or 1:35 for women; if they could not come, they could get a partial refund or have the race kit sent after the event [12].
For 2026 the regular fee is again 2,000 baht, with 1,600 baht for loyalty and ballot runners, 900 baht for runners over 60, 1,800 baht for international runners and 4,000 to 6,000 baht for late, VIP and charity places, plus a 50-baht processing fee [1]. Bibs are collected in person at the Heritage Convention Center in the Bangsaen Heritage Hotel, on Friday 18 December from noon to 8pm and Saturday 19 December from 11am to 7pm [1].
Should You Enter the 2026 Race?
Yes, if you want a closed-road half marathon with a flat course, a big field to run with and a real chance of a fast time in December's drier air. It suits runners who can get close to the top 100 and want a Sammy or Mukkie trophy, and anyone who prefers a half to the marathon-only Bangsaen42 in November.
Think twice if you expect to need close to three and a half hours, since the 2026 race enforces cut-offs at 10, 15 and 20 km, or if you are under 19. Thai residents should expect a ballot for most places.
The 2026 race is on Sunday 20 December, with a limit of 12,000 runners [1]. The organiser's route map is labelled for 2026, but the course page still says the route and service points may change, so check it before race week.
Nobody from this site ran the race. This review draws on the organiser's race information, course file and route map, the full 2025 results, airport weather records and Thai press reports.